Compounds

ABSTRACT

The present invention includes novel compounds useful in the treatment of various disorders in particular infectious diseases, cancer, and allergic diseases and other inflammatory conditions for example allergic rhinitis and asthma, and as vaccine adjuvants.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.12/031,764 filed on Feb. 15, 2008, now allowed, which claims the benefitof U.S. Provisional Application Nos. 60/890,523 filed on Feb. 19, 2007;60/972,313 filed on Sep. 14, 2007; and 61/021,921 filed on Jan. 18,2008.

BACKGROUND OF THE INVENTION

The present invention relates to compounds, processes for theirpreparation, compositions containing them, to their use in the treatmentof various disorders in particular infectious diseases, cancer, andallergic diseases and other inflammatory conditions for example allergicrhinitis and asthma, and as vaccine adjuvants.

Vertebrates are constantly threatened by the invasion of microorganismsand have evolved mechanisms of immune defense to eliminate infectivepathogens. In mammals, this immune system comprises two branches; innateimmunity and acquired immunity. The first line of host defense is theinnate immune system, which is mediated by macrophages and dendriticcells. Acquired immunity involves the elimination of pathogens at thelate stages of infection and also enables the generation ofimmunological memory. Acquired immunity is highly specific, due to thevast repertoire of lymphocytes with antigen-specific receptors that haveundergone gene rearrangement.

The innate immune response was originally thought to be non-specific,but is now known to be able to discriminate between self and a varietyof pathogens. The innate immune system recognises microbes via a limitednumber of germline-encoded pattern-recognition receptors (PRRs) whichhave a number of important characteristics. PRRs recognise microbialcomponents, known as pathogen-associated molecular patterns (PAMPs),which are essential for the survival of the microorganism. PRRs areconstitutively expressed in the host on all cells of a given type andare independent of immunological memory. These receptors include therecently-identified Toll-like receptors (TLRs), nucleotideoligomerisation domain-like receptors (NLRB) and retinoic acid-induciblegene-like receptors (RLRs) (Creagh E M, O'Neill L A., Trends Immunol.2006 27(8):352-7).

Central to the generation of an effective innate immune response inmammals are mechanisms which bring about the induction of interferonsand other cytokines which act upon cells to induce a number of effects.These effects can include the activation of anti-infective geneexpression, the activation of antigen presentation in cells to drivestrong antigen-specific immunity and the promotion of phagocytosis inphagocytic cells.

Interferon was first described as a substance which could protect cellsfrom viral infection (Isaacs & Lindemann, J. Virus Interference. Proc.R. Soc. Lon. Ser. B. Biol. Sci. 1957, 147:258-267). In man, the type Iinterferons are a family of related proteins encoded by genes onchromosome 9 and encoding at least 13 isoforms of interferon alpha(IFNα) and one isoform of interferon beta (IFNβ). Recombinant IFNα wasthe first approved biological therapeutic and has become an importanttherapy in viral infections and in cancer. As well as direct antiviralactivity on cells, interferons are known to be potent modulators of theimmune response, acting on cells of the immune system.

As a first-line therapy for hepatitis C virus (HCV) disease, interferoncombinations can be highly effective at reducing viral load and in somesubjects in eliminating viral replication. However, many patients failto show a sustained viral response and in these patients viral load isnot controlled. Additionally, therapy with injected interferon may beassociated with a number of unwanted adverse effects which are shown toaffect compliance (Dudley T, O'Donnell K, Haydon G, Mutimer D. Gut. 200655(9):1362-3).

Administration of a small molecule compound which could stimulate theinnate immune response, including the activation of type I interferonsand other cytokines, could become an important strategy for thetreatment or prevention of human diseases including viral infections.This type of immunomodulatory strategy has the potential to identifycompounds which may be useful not only in infectious diseases but incancer (Krieg. Curr. Oncol. Rep. 2004; 6(2):88-95), allergic diseases(Moisan et al., Am. J. Physiol. Lung Cell Mol. Physiol. 2005;290(5):L987-95), other inflammatory conditions such as irritable boweldisease (Rakoff-Nahoum S., Cell. 2004, 23; 118(2):229-41), and asvaccine adjuvants (Persing et al. Trends Microbiol. 2002; 10(10Suppl):532-7).

Mechanisms which lead to induction of type I interferons are only partlyunderstood. One mechanism which can lead to the induction of interferonin many cell types is the recognition of double-stranded viral RNA bythe RNA helicases RIG-I and MDA5. This mechanism is thought to be theprimary mechanism by which interferons are induced by Sendai virusinfection of cells.

Further mechanisms for the induction of interferons are viaTLR-dependent signalling events. In man, plasmacytoid dendritic cells(pDCs) are professional interferon-producing cells, able to make largeamounts of interferons in response to, for example, viral infection.These pDCs are shown to preferentially express TLR7 and TLR9 andstimulation of these receptors with viral RNA or DNA respectively caninduce expression of interferon alpha.

Oligonucleotide agonists of TLR7 and TLR9, and small moleculepurine-based agonists of TLR7 have been described which can induceinterferon alpha from these cell types in animals and in man (Takeda K.et al, Annu. Rev. Immunol., 2003, 21:335-76). TLR7 agonists includeimidazoquinoline compounds such as imiquimod and resiquimod, oxoadenineanalogues and also nucleoside analogues such as loxoribine and7-thia-8-oxoguanosine which have long been known to induce interferonalpha.

It remains unclear how small molecule purine-like compounds can inducetype I interferons and other cytokines since the molecular targets ofthese known inducers have not been identified. However, an assaystrategy has been developed to characterise small molecule inducers ofhuman interferon IFNα (regardless of mechanism) which is based onstimulation of primary human donor cells with compounds, and isdisclosed herein.

BRIEF DESCRIPTION OF THE INVENTION

The compounds of the invention have been shown to be inducers of humaninterferon and may possess an improved profile with respect to knowninducers of human interferon, for example enhanced potency. Compoundswhich induce human interferon may be useful in the treatment of variousdisorders, for example the treatment of infectious diseases, cancer, andallergic diseases and other inflammatory conditions for example allergicrhinitis and asthma, and may also be useful as vaccine adjuvants.

SUMMARY OF THE INVENTION

In a first aspect, there are provided compounds of formula (I):

wherein

-   -   R¹ is C₁₋₈alkylamino, C₁₋₈alkoxy, C₃₋₇cycloalkylC₁₋₆alkylamino,        C₃₋₇cycloalkylC₁₋₆alkoxy, C₁₋₃alkoxyC₂₋₃alkoxy, or        Het^(b)-C₁₋₃alkoxy;    -   Het^(b) is a 5- or 6-membered saturated aliphatic heterocyle        containing one oxygen atom;    -   R² is —(CH₂)_(n)-Het;    -   n is an integer having a value of 1 to 4;    -   Het is a 5- or 6-membered saturated aliphatic heterocycle        containing one oxygen heteroatom, which heterocycle may be        substituted by one or two C₁₋₄alkyl groups;        and salts and solvates thereof.

In a further embodiment, R¹ is C₁₋₆alkylamino, C₁₋₆alkoxy,C₃₋₇cycloalkylC₁₋₆alkylamino, C₃₋₇cycloalkylC₁₋₆alkoxy,C₁₋₃alkoxyC₂₋₃alkoxy, or Het^(b)-C₁₋₃alkoxy.

In a further embodiment, R¹ is n-butoxy, n-butylamino,2,2-dimethylpentyloxy, n-pentylamino, 3-methylbutoxy, 2-methylbutoxy,1-methylbutoxy, 2-methylbutylamino, 3-methylbutylamino,1-methylbutylamino, 2-(cyclopropyl)ethoxy, 2-(ethoxy)ethoxy,(1-methyl-2-methoxy)ethoxy, cyclohexylmethylamino,cyclopentylmethylamino, 2-(cyclopropyl)ethylamino, 2-(methyl)propoxy,cyclohexylmethoxy, methoxyethoxy, (2-tetrahydrofuranyl)methoxy,(2-tetrahydro-2H-pyranyl)methoxy, or 2-(iso-propoxy)ethoxy.

In a further embodiment, R¹ is n-butylamino, n-butoxy, or2-(cyclopropyl)ethoxy.

In a further embodiment, R¹ is n-butylamino, n-butoxy,(R)-1-methylbutyloxy, (S)-1-methylbutyloxy, or 2-(cyclopropyl)ethoxy.

In a further embodiment, n is 1.

In a further embodiment, n is 2.

In a further embodiment, n is 3.

In a further embodiment, n is 4.

In a further embodiment, Het is tetrahydrofuran-3-yl,tetrahydro-2H-pyran-3-yl, tetrahydro-2H-pyran-4-yl,tetrahydrofuran-2-yl, 2,2-dimethyltetrahydro-2H-pyran-4-yl, ortetrahydro-2H-pyran-2-yl.

In a further embodiment, Het is tetrahydro-2H-pyran-4-yl,tetrahydrofuran-2-yl, tetrahydro-2H-pyran-3-yl,tetrahydro-2H-pyran-2-yl, or tetrahydrofuran-3-yl.

In a further embodiment, Het is tetrahydro-2H-pyran-3-yl.

In a further embodiment, Het is tetrahydro-2H-pyran-4-yl,tetrahydro-2H-pyran-3-yl, tetrahydro-2H-pyran-2-yl,2,2-dimethyltetrahydro-2H-pyran-4-yl, tetrahydrofuran-3-yl, ortetrahydro-2H-pyran-2-yl.

In a further embodiment, when n is 1, then Het is tetrahydrofuran-3-yl,tetrahydro-2H-pyran-3-yl, tetrahydro-2H-pyran-4-yl,tetrahydrofuran-2-yl, 2,2-dimethyltetrahydro-2H-pyran-4-yl, ortetrahydro-2H-pyran-2-yl.

In a further embodiment, when n is 2, then Het istetrahydro-2H-pyran-4-yl, tetrahydrofuran-2-yl,tetrahydro-2H-pyran-3-yl, tetrahydro-2H-pyran-2-yl, ortetrahydrofuran-3-yl.

In a further embodiment, when n is 3, then Het istetrahydro-2H-pyran-3-yl.

In a further embodiment, when n is 4, then Het istetrahydro-2H-pyran-3-yl.

In a further embodiment, when n is 1, then R² istetrahydro-2H-pyran-4-yl or tetrahydrofuran-3-yl.

In a further embodiment, when n is 2, then Het istetrahydro-2H-pyran-4-yl, tetrahydro-2H-pyran-3-yl,tetrahydro-2H-pyran-2-yl, 2,2-dimethyltetrahydro-2H-pyran-4-yl,tetrahydrofuran-3-yl, or tetrahydrofuran-2-yl.

In a further embodiment, when n is 3, then Het istetrahydro-2H-pyran-4-yl, tetrahydro-2H-pyran-3-yl,tetrahydro-2H-pyran-2-yl, 2,2-dimethyltetrahydro-2H-pyran-4-yl,tetrahydrofuran-3-yl, or tetrahydrofuran-2-yl.

In a further embodiment, when n is 4, then Het istetrahydro-2H-pyran-4-yl, tetrahydro-2H-pyran-3-yl,tetrahydro-2H-pyran-2-yl, 2,2-dimethyltetrahydro-2H-pyran-4-yl,tetrahydrofuran-3-yl, or tetrahydrofuran-2-yl.

In a further aspect of the invention, there is provided a subset ofcompounds of formula (I), being compounds of formula (I′):

wherein

-   -   R^(1′) is n-butylamino, n-butoxy, or cyclopropylethoxy;    -   R^(2′) is —(CH₂)_(n′)-Het′;    -   n′ is 1;    -   Het′ is tetrahydro-2H-pyran-4-yl or tetrahydro-3-furanyl;        and salts and solvates thereof.

In a further aspect of the invention, there is provided a subset ofcompounds of formula (I), being compounds of formula (I″):

wherein

-   -   R^(1″) is n-butylamino, n-butoxy, (R)-1-methylbutyloxy,        (S)-1-methylbutyloxy, or 2-(cyclopropyl)ethoxy;    -   R^(2″) is —(CH₂)_(n″)-Het″;    -   n″ is 2, 3, or 4;    -   Het″ is tetrahydro-2H-pyran-4-yl, tetrahydro-2H-pyran-3-yl,        tetrahydro-2H-pyran-2-yl, 2,2-dimethyltetrahydro-2H-pyran-4-yl,        tetrahydrofuran-3-yl, or tetrahydrofuran-2-yl;        and salts and solvates thereof.

In a further aspect of the invention, there is provided a subset ofcompounds of formula (I), being compounds of formula (IA):

wherein

-   -   R^(1A) is C₁₋₆alkylamino, or C₁₋₆alkoxy;    -   R^(2A) is —(CH₂)_(n) _(A) -Het^(A);    -   n^(A) is an integer having a value of 1 to 4;    -   Het^(A) is a 5- or 6-membered saturated aliphatic heterocycle        containing one oxygen heteroatom;        and salts and solvates thereof.

In a further embodiment, R^(1A) is n-butoxy or n-butylamino.

In a further embodiment, n^(A) is 1 or 2.

In a further embodiment, when n^(A) is 1, then Het^(A) istetrahydrofuran-3-yl, tetrahydro-2H-pyran-3-yl, ortetrahydro-2H-pyran-4-yl.

Examples of compounds of formula (I) are provided in the following list,and form a further aspect of the invention:

-   6-amino-2-butoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butoxy-9-(tetrahydro-2H-pyran-2-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butoxy-9-(tetrahydrofuran-2-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butylamino-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butylamino-9-(tetrahydro-2H-pyran-2-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butylamino-9-(tetrahydrofuran-2-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butylamino-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butylamino-9-(tetrahydrofuran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butylamino-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butoxy-9-(tetrahydrofuran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butoxy-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butoxy-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butoxy-9-[2-(tetrahydrofuran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butylamino-9-[2-(tetrahydrofuran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butoxy-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butylamino-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2,2-dimethylpentyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(pentylamino)-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(3-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(1-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-methylbutyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(3-methylbutyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(1-methylbutyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butyloxy-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butyloxy-9-[(2,2-dimethyltetrahydro-2H-pyran-4-yl)methyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[(2,2-dimethyltetrahydro-2H-pyran-4-yl)methyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-butyloxy-9-[2-(tetrahydro-3-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[2-(tetrahydro-3-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,    isomer 1;-   6-amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,    isomer 2;-   6-amino-2-{[2-(ethyloxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[1-methyl-2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[2-(ethyloxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[1-methyl-2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(cyclohexylmethyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(cyclopentylmethyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,    isomer 1;-   6-amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,    isomer 2;-   6-amino-2-[(2-methylpropyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(cyclohexylmethyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[2-(methoxy)ethyl]oxy}-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(tetrahydro-2-furanylmethyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[3-(tetrahydro-2H-pyran-3-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-9-(tetrahydro-2H-pyran-4-ylmethyl)-2-[(tetrahydro-2H-pyran-2-ylmethoxy]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-({2-[(1-methylethyl)oxy]ethyl}oxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)amino]-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)amino]-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,    isomer 1, and;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[tetrahydro-3-furanylmethyl]-7,9-dihydro-8H-purin-8-one,    isomer 2;    and salts and solvates thereof.

The following compounds of formula (I) form a further aspect of theinvention:

-   6-amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,    isomer 1;-   6-amino-2-butylamino-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,    isomer 2;-   6-amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,    isomer 1;-   6-amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,    isomer 2;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,    isomer 1, and;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[tetrahydro-3-furanylmethyl]-7,9-dihydro-8H-purin-8-one,    isomer 2;    and salts and solvates thereof.

The following compounds of formula (I) form a further aspect of theinvention:

-   6-amino-2-butoxy-9-[2-(tetrahydrofuran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one,    isomer 1;-   6-amino-2-butoxy-9-[2-(tetrahydrofuran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one,    isomer 2;-   6-amino-2-butylamino-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one.    isomer 1;-   6-amino-2-butylamino-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one.    isomer 2;-   6-amino-2-butyloxy-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one,    isomer 1;-   6-amino-2-butyloxy-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one,    isomer 2;-   6-amino-2-butyloxy-9-[(2,2-dimethyltetrahydro-2H-pyran-4-yl)methyl]-7,9-dihydro-8H-purin-8-one,    isomer 1;-   6-amino-2-butyloxy-9-[(2,2-dimethyltetrahydro-2H-pyran-4-yl)methyl]-7,9-dihydro-8H-purin-8-one,    isomer 2;-   6-amino-2-(butylamino)-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[4-(tetrahydro-2-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butylamino)-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-[4-(tetrahydro-2-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-[3-(tetrahydro-2H-pyran-3-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-ylethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-(butyloxy)-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-2-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-2-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-3-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-2H-pyran-2-ylethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-2H-pyran-3-ylethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-2H-pyran-4-ylethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-ylethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-2-{[(1S)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one;-   6-amino-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-2-{[(1S)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one;-   6-amino-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-2-{[(1S)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;-   6-amino-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-2-{[(1R)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one;-   6-amino-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-2-{[(1R)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one;-   6-amino-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-2-{[(1R)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one;    and salts and solvates thereof.

There is thus provided as a further aspect of the invention a compoundof formula (I), or a pharmaceutically acceptable salt or solvatethereof, for use as an active therapeutic agent.

There is also therefore provided a compound of formula (I), or apharmaceutically acceptable salt or solvate thereof, for use in thetreatment of infectious diseases, cancer, allergic diseases and otherinflammatory conditions.

There is also therefore provided a compound of formula (I), or apharmaceutically acceptable salt or solvate thereof, for use as avaccine adjuvant.

There is further provided the use of a compound of formula (I), or apharmaceutically acceptable salt or solvate thereof, for the manufactureof a medicament for the treatment of infectious diseases, cancer,allergic diseases and other inflammatory conditions.

In a further aspect of the invention, there is provided a method for thetreatment of infectious diseases, cancer, allergic diseases and otherinflammatory conditions, which method comprises administering aneffective amount of a compound of formula (I), or a pharmaceuticallyacceptable salt or solvate thereof.

The invention thus provides, in a further aspect, a combinationcomprising at least one compound of formula (I), or pharmaceuticallyacceptable salts or solvates thereof, together with at least one othertherapeutically active agent.

There is further provided a pharmaceutical composition comprising acompound of formula (I), or a pharmaceutically acceptable salt orsolvate thereof, and optionally one or more pharmaceutically acceptablediluents or carriers.

There is also provided a process for preparing a pharmaceuticalcomposition which comprises admixing a compound of formula (I), or apharmaceutically acceptable salt or solvate thereof, with one or morepharmaceutically acceptable diluents or carriers.

The compounds of formula (I) and salts and solvates thereof may beprepared by the methodology described herein, and constitutes a furtheraspect of this invention.

Accordingly, there is provided a process for the preparation of acompound of formula (I), which process comprises the deprotection of acompound of formula (IIA):

wherein R¹ and R² are as hereinbefore defined for a compound of formula(I) and R³ is C₁₋₆alkyl, and thereafter, if required, carrying out oneor more of the following optional steps:(i). converting a compound of formula (I) to a further compound offormula (I);(ii). preparing a salt or solvate of the compound so-formed.

In one aspect of the invention, a compound of formula (IIA) may beprepared by reaction of a compound of formula (II):

wherein R¹ is as hereinbefore defined for a compound of formula (I) andR³ is as hereinbefore defined for a compound of formula (IIA), with acompound of formula (IIB):

R²-L  (IIB)

wherein R² is as hereinbefore defined for a compound of formula (I) andL is a suitable leaving group, for example an alkylsulphonyloxy groupsuch as a methanesulphonyloxy group, or a halogen atom, such as bromine.

In one aspect of the invention, a compound of formula (II) is used inthe form of a salt, for example the trifluoroacetate salt. This saltresults from the deprotection of a compound of formula (III) with, forexample, trifluoroacetic acid, as hereinbelow described.

Alternatively, a compound of formula (I) may be prepared by reaction ofa compound of formula (II) as hereinbefore defined, typically as a salt,for example the trifluoroacetate salt, with a compound of formula (IIB)as hereinbefore defined, without isolation of the intermediate compound(IIA).

In one aspect of the invention, a compound of formula (II) may beprepared by reaction of a compound of formula (III):

wherein R¹ is as hereinbefore defined for a compound of formula (I), Pis a protecting group, typically a tetrahydro-2H-pyran-2-yl group, andR³ is as hereinbefore defined for a compound of formula (IIA), with asuitable deprotecting agent, for example trifluoroacetic acid (the useof trifluoroacetic acid results in a compound of formula (II) beingformed as a trifluoroacetate salt).

In one aspect of the invention, a compound of formula (IIB) wherein L isa halogen atom may be prepared by reaction of a compound of formula(IX):

R²—OG  (IX)

wherein R² is as hereinbefore defined for a compound of formula (I) andOG is a leaving group, for example an alkanesulphonate group such as amethanesulphonate group, with an anhydrous alkali metal halide such asanhydrous lithium bromide.

In one aspect of the invention, a compound of formula (IX), or acompound of formula (IIB) wherein L is an alkylsulphonyl group, may beprepared by reaction of a compound of formula (X):

R²—OH  (X)

wherein R² is as hereinbefore defined for a compound of formula (I),with a suitable activating agent, for example an alkylsulphonyl halidesuch as methanesulphonyl chloride.

In one aspect of the invention, a compound of formula (X) may beprepared by reaction of a compound of formula (XI):

Het-(CH₂)_((n-1))—COOC₁₋₆alkyl  (XI)

wherein Het and n are as hereinbefore defined for a compound of formula(I) with a suitable reducing agent, such as lithium aluminium hydride.

In one aspect of the invention, a compound of formula (X) wherein Het is3-tetrahydropyranyl and n is an integer having a value of 2 may beprepared by reaction of the compound of formula (XII):

Het-(CH₂)—CHO  (XII)

wherein Het is 3-tetrahydropyranyl, with a suitable reducing agent, forexample sodium borohydride.

In one aspect of the invention, a compound of formula (XII) may beprepared by reaction of a compound of formula (XIII):

Het-CH═CH(OC₁₋₆alkyl)  (XIII)

wherein Het is 3-tetrahydropyranyl, with a suitable mineral acid, forexample hydrochloric acid.

In one aspect of the invention, a compound of formula (XIII) may beprepared by reaction of the compound of formula (XIV):

Het-CHO  (XIV)

wherein Het is 3-tetrahydropyranyl, with a compound of formula (XV):

C₁₋₆alkoxy-(CH₂)—P⁺(Ph)₃Cl⁻  (XV)

In one aspect of the invention, a compound of formula (XIV) may beprepared by hydrogenation of the compound of formula (XVI):

In one aspect of the invention, a compound of formula (III) may beprepared by reaction of a compound of formula (IV):

wherein R¹ is as hereinbefore defined for a compound of formula (I), Pis as hereinbefore defined for a compound of formula (III), and X is ahalogen atom, for example bromine, with an alkali metal alkoxide, forexample sodium methoxide.

In one aspect of the invention, a compound of formula (IV) may beprepared by reaction of a compound of formula (V):

wherein R¹ is as hereinbefore defined for a compound of formula (I) andP is as hereinbefore defined for a compound of formula (III), with asuitable halogenating agent, for example N-bromosuccinimide.

In one aspect of the invention, a compound of formula (V), wherein R¹ isC₁₋₈alkoxy, C₃₋₇cycloalkylC₁₋₆alkoxy, C₁₋₆alkoxyC₁₋₆alkoxy, orHet^(b)-C₁₋₃alkoxy, may be prepared by reaction of a compound of formula(VI):

wherein P is as hereinbefore defined for a compound of formula (III) andY is a halogen atom, for example chlorine, with a compound of formula(VIA):

R¹—H  (VIA)

wherein R¹ is C₁₋₈alkoxy, C₃₋₇cycloalkylC₁₋₈alkoxy,C₁₋₆alkoxyC₁₋₆alkoxy, or Het^(b)-C₁₋₃alkoxy, in the presence of a strongbase of appropriate strength, for example sodium metal, sodium hydride,or sodium tert-butoxide.

In one aspect of the invention, a compound of formula (V), wherein R¹ isC₁₋₈alkylamino or C₃₋₇cycloalkylC₁₋₆alkylamino may be prepared byreaction of a compound of formula (VI) as hereinbefore defined, with acompound of formula (VIB):

R¹—H  (VIB)

wherein R¹ is C₁₋₆alkylamino or C₃₋₇cycloalkylC₁₋₆amino.

In one aspect of the invention, a compound of formula (VI) may beprepared by reaction of a compound of formula (VII):

wherein P is as hereinbefore defined for a compound of formula (III), Yis as hereinbefore defined for a compound of formula (VI), and Z is ahalogen atom, for example chlorine, with an alcoholic solution ofammonia.

In one aspect of the invention, a compound of formula (VII) may beprepared from a compound of formula (VIII):

wherein Y is as hereinbefore defined for a compound of formula (VI) andZ is as hereinbefore defined for a compound of formula (VII), byreaction with a suitable protecting reagent, for example3,4-dihydro-2H-pyran.

There is further provided in a further aspect of the invention, aprocess for the preparation of a compound of formula (I), which processcomprises the hydrolysis of a compound of formula (XXI):

wherein R¹ and R² are as hereinbefore defined for a compound of formula(I) and X is as hereinbefore defined for a compound of formula (IV).

In one aspect of the invention, a compound of formula (XXI) wherein maybe prepared by halogenation of a compound of formula (XX):

wherein R¹ and R² are as hereinbefore defined for a compound of formula(I).

In one aspect of the present invention, a compound of formula (XX),wherein R¹ is C₁₋₈alkoxy, C₃₋₇cycloalkylC₁₋₆alkoxy,C₁₋₆alkoxyC₁₋₆alkoxy, or Het^(b)-C₁₋₃alkoxy may be prepared by reactionof a compound of formula (XIX):

wherein Y is as hereinbefore defined for a compound of formula (VI) andR² is as hereinbefore defined for a compound of formula (I), with acompound of formula (VIA) as hereinbefore defined.

In one aspect of the invention, a compound of formula (XIX) may beprepared by reaction of a compound of formula (XVIII):

wherein Y is as hereinbefore defined for a compound of formula (VI), Zis as hereinbefore defined for a compound of formula (VII), and R² is ashereinbefore defined for a compound of formula (I), with ammonia.

A compound of formula (XIX) may also be prepared by reaction of acompound of formula (XVII):

wherein Y is as hereinbefore defined for a compound of formula (VI),with a compound of formula (IIB) as hereinbefore defined.

In one aspect of the invention, a compound of formula (XVIII) may beprepared by reaction of a compound of formula (VIII) as hereinbeforedefined with a compound of formula R²—OH, wherein R² is as hereinbeforedefined for a compound of formula (I).

In one aspect of the invention, a compound of formula (XVII) may beprepared by reaction of a compound of formula (VIII) as hereinbeforedefined with ammonia.

In a further aspect of the invention, a compound of formula (I), whereinR¹ is C₁₋₈alkylamino or C₃₋₇cycloalkylC₁₋₆alkylamino, may be prepared byreaction of a compound of formula (XXIII):

wherein Y is as hereinbefore defined for a compound of formula (VI), R²is as hereinbefore defined for a compound of formula (I), and R³ is ashereinbefore defined for a compound of formula (IIA), with a compound offormula (VIB) as hereinbefore defined.

In one aspect of the invention, a compound of formula (XXIII) may beprepared by reaction of a compound of formula (XXII):

wherein X is as hereinbefore defined for a compound of formula (IV), Yis as hereinbefore defined for a compound of formula (VI) and R² is ashereinbefore defined for a compound of formula (I), with a source ofalkoxide anion.

The present invention covers all combinations of embodiments and aspectsherein described.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an XRPD diffractogram of6-amino-2-butylamino-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one.

FIG. 2 shows an XRPD diffractogram of6-amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,Isomer 1.

FIG. 3 shows an XRPD diffractogram of6-amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,Isomer 2.

FIG. 4 shows an XRPD diffractogram of6-amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,Isomer 1.

FIG. 5 shows an XRPD diffractogram of6-amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,Isomer 2.

FIG. 6 shows an XRPD diffractogram of6-amino-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,Isomer 1

FIG. 7 shows an XRPD diffractogram of6-amino-2-[(2-cyclopropylethyl)oxy]-9-[tetrahydro-3-furanylmethyl]-7,9-dihydro-8H-purin-8-one,Isomer 2.

FIG. 8 shows a DSC thermogram of6-amino-2-butylamino-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one.

FIG. 9 shows a DSC thermogram of6-amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,Isomer 1.

FIG. 10 shows a DSC thermogram of6-amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,Isomer 2.

FIG. 11 shows a DSC thermogram of6-amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,Isomer 2.

FIG. 12 shows a DSC thermogram of6-amino-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,Isomer 1.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is described in terms known and appreciated bythose skilled in the art. For ease of reference certain termshereinafter are defined. The fact that certain terms are defined,however, should not be considered as indicative that defined terms areused in a manner inconsistent with the ordinary meaning or,alternatively, that any term that is undefined is indefinite or not usedwithin the ordinary and accepted meaning. Rather, all terms used hereinare believed to describe the invention such that one of ordinary skillcan appreciate the scope of the present invention. The followingdefinitions are meant to clarify, but not limit, the terms defined.

References to ‘alkyl’ include references to both straight-chain andbranched-chain aliphatic isomers of the corresponding alkyl, suitablycontaining up to eight carbon atoms, for example up to four carbon atomsor up to three carbon atoms. Such references to ‘alkyl’ are alsoapplicable when an alkyl group is part of another group, for example analkylamino or alkoxy group. Examples of such alkyl groups and groupscontaining alkyl groups are C₁₋₆alkyl, C₁₋₆alkylamino, C₁₋₈alkoxy,C₃₋₇cycloalkylC₁₋₆alkylamino, C₃₋₇cycloalkylC₁₋₆alkoxy, andC₁₋₃alkoxyC₂₋₃alkoxy.

References to ‘heterocycle’ or ‘heterocyclyl’ refer to monocyclicsaturated heterocyclic aliphatic rings containing 5 or 6 carbon atoms,and one heteroatom, which heteroatom is oxygen. Examples of suchheterocyclic rings are tetrahydrofuranyl and tetrahydropyranyl.

References to ‘cycloalkyl’ refer to monocyclic alkyl groups containingbetween three and seven carbon atoms, for example three carbon atoms, orfive carbon atoms, or six carbon atoms. Examples of such cycloalkylgroups are cyclopropyl, cyclopentyl, and cyclohexyl.

References to ‘halogen’ refer to iodine, bromine, chlorine or fluorine,typically bromine or chlorine.

It is to be understood that references hereinafter to compounds of theinvention mean a compound of formula (I) as the free base, or as a salt,or as a solvate.

It will be appreciated from the foregoing that included within the scopeof the invention are all solvates, hydrates, complexes, isomers andpolymorphic forms of the compounds of formula (I) and salts and solvatesthereof.

Salts of the compounds of formula (I) include pharmaceuticallyacceptable salts and salts which may not be pharmaceutically acceptablebut may be useful in the preparation of compounds of formula (I) andpharmaceutically acceptable salts thereof. Salts may be derived fromcertain inorganic or organic acids, or certain inorganic or organicbases.

The invention includes within its scope all possible stoichiometric andnon-stoichiometric forms of the salts of the compounds of formula (I).

Examples of salts are pharmaceutically acceptable salts.Pharmaceutically acceptable salts include acid addition salts and baseaddition salts. For a review on suitable salts see Berge et al., J.Pharm. Sci., 66:1-19 (1977).

Examples of pharmaceutically acceptable acid addition salts of acompound of formula (I) include hydrobromide, hydrochloride, sulphate,p-toluenesulphonate, methanesulphonate, naphthalenesulphonate, andphenylsulphonate salts.

Examples of pharmaceutically acceptable base salts include alkali metalsalts such as those of sodium and potassium, and alkaline earth metalsalts such as those of calcium and magnesium.

Salts may be formed using techniques well-known in the art, for exampleby precipitation from solution followed by filtration, or by evaporationof the solvent.

Typically, a pharmaceutically acceptable acid addition salt can beformed by reaction of a compound of formula (I) with a suitable strongacid (such as hydrobromic, hydrochloric, sulphuric, p-toluenesulphonic,methanesulphonic or naphthalenesulphonic acids), optionally in asuitable solvent such as an organic solvent, to give the salt which isusually isolated for example by crystallisation and filtration.

It will be appreciated that many organic compounds can form complexeswith solvents in which they are reacted or from which they areprecipitated or crystallised. These complexes are known as “solvates”.For example, a complex with water is known as a “hydrate”. Solvents withhigh boiling points and/or solvents with a high propensity to formhydrogen bonds such as water, ethanol, iso-propyl alcohol, andN-methylpyrrolidinone may be used to form solvates. Solvates of thecompounds of formula (I) are within the scope of the invention. As usedherein, the term solvate encompasses solvates of both a free basecompound as well as any salt thereof.

Certain of the compounds of the invention may contain chiral atomsand/or multiple bonds, and hence may exist in one or more stereoisomericforms. The present invention encompasses all of the stereoisomers of thecompounds of the invention, including geometric isomers and opticalisomers, whether as individual stereoisomers or as mixtures thereofincluding racemic modifications. Any stereoisomer may contain less than10% by weight, for example less than 5% by weight, or less than 0.5% byweight, of any other stereoisomer. For example, any optical isomer maycontain less than 10% by weight, for example less than 5% by weight, orless than 0.5% by weight, of its antipode.

As used herein, the terms “Isomer 1” and “Isomer 2” and “Diastereoisomer1” and “Diastereoisomer 2” refer to the first- and second-eluting isomeror diastereoisomer respectively when the separations are performed usingthe chromatographic conditions specified in the relevant text. It willbe appreciated that the order of elution may change depending on theparticular chromatographic conditions employed.

Certain of the compounds of the invention may exist in tautomeric forms.It will be understood that the present invention encompasses all of thetautomers of the compounds of the invention whether as individualtautomers or as mixtures thereof.

The compounds of the invention may be in crystalline or amorphous form.Furthermore, some of the crystalline forms of the compounds of theinvention may exist as polymorphs, all of which are included within thescope of the present invention. The most thermodynamically stablepolymorphic form or forms of the compounds of the invention are ofparticular interest.

Examples of disease states in which the compounds of formula (I) andpharmaceutically acceptable salts or solvates thereof have potentiallybeneficial effects include infectious diseases, cancer, allergicdiseases and other inflammatory conditions. The compounds of formula (I)and pharmaceutically acceptable salts or solvates thereof are also ofpotential use as vaccine adjuvants.

The compounds of formula (I) and pharmaceutically acceptable salts orsolvates thereof may therefore be useful in the treatment of variousdisorders, in particular the treatment of infectious diseases including,but not limited to, those caused by hepatitis viruses (e.g. hepatitis Bvirus, hepatitis C virus), human immunodeficiency virus,papillomaviruses, herpesviruses, respiratory viruses (e.g. influenzaviruses, respiratory syncytial virus, rhinovirus, metapneumovirus,parainfluenzavirus, SARS), and West Nile virus. The compounds of formula(I) and pharmaceutically acceptable salts or solvates thereof may alsobe useful in the treatment of microbial infections caused by, forexample, bacteria, fungi, or protozoa. These include, but are notlimited to, tuberculosis, bacterial pneumonia, aspergillosis,histoplasmosis, candidosis, pneumocystosis, leprosy, chlamydia,cryptococcal disease, cryptosporidosis, toxoplasmosis, leishmania,malaria, and trypanosomiasis.

As potent modulators of the immune response the compounds of formula (I)and pharmaceutically acceptable salts or solvates thereof may thereforebe useful in the treatment of inflammation, including but not limited toinflammatory or allergic diseases such as asthma, allergic rhinitis,hypersensitivity lung diseases, eosinophilic pneumonitis, delayed-typehypersensitivity, atherosclerosis, pancreatitis, gastritis,osteoarthritis, psoriasis, sarcoidosis, pulmonary fibrosis, respiratorydistress syndrome, bronchiolitis, chronic obstructive pulmonary disease,sinusitis, cystic fibrosis, and dermatitis.

The compounds of formula (I) and pharmaceutically acceptable salts orsolvates thereof may also be useful in the treatment of autoimmunediseases including but not limited to rheumatoid arthritis, psoriaticarthritis, systemic lupus erythematosus, sjöegrens disease, ankylosingspondylitis, scleroderma, diabetes, graft rejection, includinggraft-versus-host disease, inflammatory bowel diseases including, butnot limited to, Crohn's disease and ulcerative colitis.

The compounds of formula (I) and pharmaceutically acceptable salts orsolvates thereof may also be useful in the treatment of various cancers,in particular the treatment of cancers that are known to be responsiveto immunotherapy and including, but not limited to, renal cellcarcinoma, lung cancer, breast cancer, colo-rectal cancer, bladdercancer, melanoma, leukaemia, lymphomas and ovarian cancer.

It will be appreciated by those skilled in the art that referencesherein to treatment or therapy extend to prophylaxis as well as thetreatment of established conditions.

As mentioned herein, compounds of formula (I) and pharmaceuticallyacceptable salts or solvates thereof may be useful as therapeuticagents.

As noted, the present invention includes a compound of formula (I), or apharmaceutically acceptable salt or solvate thereof, for use as anactive therapeutic agent.

There is also therefore provided a compound of formula (I), or apharmaceutically acceptable salt or solvate thereof, for use in thetreatment of infectious diseases, cancer, allergic diseases and otherinflammatory conditions.

There is also therefore provided a compound of formula (I), or apharmaceutically acceptable salt or solvate thereof, for use as avaccine adjuvant.

There is also therefore provided a compound of formula (I), or apharmaceutically acceptable salt or solvate thereof, for use in thetreatment of allergic rhinitis.

There is also therefore provided a compound of formula (I), or apharmaceutically acceptable salt or solvate thereof, for use in thetreatment of asthma.

There is further provided the use of a compound of formula (I), or apharmaceutically acceptable salt or solvate thereof, for the manufactureof a medicament for the treatment of infectious diseases, cancer,allergic diseases and other inflammatory conditions.

The present invention also includes a method for the treatment ofinfectious diseases, cancer, allergic diseases and other inflammatoryconditions, which method comprises administering an effective amount ofa compound of formula (I), or a pharmaceutically acceptable salt orsolvate thereof.

There is further provided the use of a compound of formula (I), or apharmaceutically acceptable salt or solvate thereof, for the manufactureof a medicament for the treatment of allergic rhinitis.

The present invention also includes a method for the treatment ofallergic rhinitis, which method comprises administering an effectiveamount of a compound of formula (I), or a pharmaceutically acceptablesalt or solvate thereof.

There is further provided the use of a compound of formula (I), or apharmaceutically acceptable salt or solvate thereof, for the manufactureof a medicament for the treatment of asthma.

The present invention also includes a method for the treatment ofasthma, which method comprises administering an effective amount of acompound of formula (I), or a pharmaceutically acceptable salt orsolvate thereof.

The compounds according to the invention, and pharmaceuticallyacceptable salts and solvates thereof, may be formulated foradministration in any convenient way.

The compounds according to the invention, and pharmaceuticallyacceptable salts and solvates thereof, may, for example, be formulatedfor oral, topical, inhaled, intranasal, buccal, parenteral (for exampleintravenous, subcutaneous, intradermal, or intramuscular) or rectaladministration. In one aspect, the compounds of formula (I), andpharmaceutically acceptable salts and solvates thereof, are formulatedfor oral administration. In a further aspect, the compounds of formula(I), and pharmaceutically acceptable salts and solvates thereof, areformulated for topical administration, for example intranasaladministration.

Tablets and capsules for oral administration may contain conventionalexcipients such as binding agents, for example syrup, acacia, gelatin,sorbitol, tragacanth, mucilage of starch, cellulose or polyvinylpyrrolidone; fillers, for example, lactose, microcrystalline cellulose,sugar, maize-starch, calcium phosphate or sorbitol; lubricants, forexample, magnesium stearate, stearic acid, talc, polyethylene glycol orsilica; disintegrants, for example, potato starch, croscarmellose sodiumor sodium starch glycollate; or wetting agents such as sodium laurylsulphate. The tablets may be coated according to methods well known inthe art.

Oral liquid preparations may be in the form of, for example, aqueous oroily suspensions, solutions, emulsions, syrups or elixirs, or may bepresented as a dry product for constitution with water or other suitablevehicle before use. Such liquid preparations may contain conventionaladditives such as suspending agents, for example, sorbitol syrup, methylcellulose, glucose/sugar syrup, gelatin, hydroxymethyl cellulose,carboxymethyl cellulose, aluminium stearate gel or hydrogenated ediblefats; emulsifying agents, for example, lecithin, sorbitan mono-oleate oracacia; non-aqueous vehicles (which may include edible oils), forexample almond oil, fractionated coconut oil, oily esters, propyleneglycol or ethyl alcohol; or preservatives, for example, methyl or propylp-hydroxybenzoates or sorbic acid. The preparations may also containbuffer salts, flavouring, colouring and/or sweetening agents (e.g.mannitol) as appropriate.

Formulations for intranasal administration include aqueous formulationsadministered to the nose by drops or by pressurised pump. Suitableformulations contain water as the diluent or carrier for this purpose.Aqueous formulations for administration to the lung or nose may beprovided with conventional excipients such as buffering agents, tonicitymodifying agents and the like. Aqueous formulations may also beadministered to the nose or other regions of the respiratory tract bynebulisation.

Formulations for inhaled administration include aqueous, organic oraqueous/organic mixtures, dry powder or crystalline formulationsadministered to the respiratory tract by pressurised pump or inhaler.Suitable formulations contain water as the diluent or carrier for thispurpose and may be provided with conventional excipients such asbuffering agents, tonicity modifying agents and the like. Aqueousformulations may also be administered to the nose and other regions ofthe respiratory tract by nebulisation. Such formulations may be aqueoussolutions or suspensions or aerosols delivered from pressurised packs,such as a metered dose inhaler, with the use of a suitable liquefiedpropellant. Aerosol compositions suitable for inhalation can be either asuspension or a solution and may contain a compound of formula (I) or asalt or solvate thereof and a suitable propellant such as a fluorocarbonor hydrogen-containing chlorofluorocarbon or mixtures thereof,particularly hydrofluoroalkanes, especially 1,1,1,2-tetrafluoroethane,1,1,1,2,3,3,3-heptafluoro-n-propane or a mixture thereof. The aerosolcomposition may optionally contain additional formulation excipientswell known in the art such as surfactants e.g. oleic acid, lecithin oran oligolactic acid or derivative thereof e.g. as described in WO94/21229 and WO 98/34596 (Minnesota Mining and Manufacturing Company)and co-solvents e.g. ethanol.

Ointments, creams and gels, may, for example, be formulated with anaqueous or oily base with the addition of suitable thickening and/orgelling agent and/or solvents. Such bases may thus, for example, includewater and/or an oil such as liquid paraffin or a vegetable oil such asarachis oil or castor oil, or a solvent such as polyethylene glycol.Thickening agents and gelling agents which may be used according to thenature of the base include soft paraffin, aluminium stearate,cetostearyl alcohol, polyethylene glycols, wool-fat, beeswax,carboxypolymethylene and cellulose derivatives, and/or glycerylmonostearate and/or non-ionic emulsifying agents.

Lotions may be formulated with an aqueous or oily base and will ingeneral also contain one or more emulsifying agents, stabilising agents,dispersing agents, suspending agents or thickening agents.

Powders for external application may be formed with the aid of anysuitable powder base, for example, talc, lactose or starch. Drops may beformulated with an aqueous or non-aqueous base also comprising one ormore dispersing agents, solubilising agents, suspending agents orpreservatives.

The compounds according to the invention and pharmaceutically acceptablesalts or solvates thereof may, for example, be formulated fortransdermal delivery by formulation into patches or other devices (e.g.pressurised gas devices) which deliver the active component into theskin.

For buccal administration the compositions may take the form of tabletsor lozenges formulated in the conventional manner.

The compounds and pharmaceutically acceptable salts or solvates thereofmay also be formulated as suppositories, e.g. containing conventionalsuppository bases such as cocoa butter or other glycerides.

The compounds according to the invention or pharmaceutically acceptablesalts or solvates thereof may also be formulated for parenteraladministration by bolus injection or continuous infusion and may bepresented in unit dose form, for instance as ampoules, vials, smallvolume infusions or pre-filled syringes, or in multidose containers withan added preservative. The compositions may take such forms assolutions, suspensions, or emulsions in aqueous or non-aqueous vehicles,and may contain formulatory agents such as anti-oxidants, buffers,antimicrobial agents and/or tonicity adjusting agents. Alternatively,the active ingredient may be in powder form for constitution with asuitable vehicle, e.g. sterile, pyrogen-free water, before use. The drysolid presentation may be prepared by filling a sterile powderaseptically into individual sterile containers or by filling a sterilesolution aseptically into each container and freeze-drying.

The compounds according to the invention or pharmaceutically acceptablesalts or solvates thereof may also be formulated with vaccines asadjuvants to modulate their activity. Such formulations may containantibody(ies) or antibody fragment(s) or an antigenic componentincluding but not limited to protein, DNA, live or dead bacteria and/orviruses or virus-like particles, together with one or more componentswith adjuvant activity including but not limited to aluminium salts, oiland water emulsions, heat shock proteins, lipid A preparations andderivatives, glycolipids, other TLR agonists such as CpG DNA or similaragents, cytokines such as GM-CSF or IL-12 or similar agents.

The compounds of the present invention or pharmaceutically acceptablesalts or solvates thereof may be employed alone or in combination withother therapeutic agents. The compound(s) of the present invention orpharmaceutically acceptable salts or solvates thereof and the otherpharmaceutically active agent(s) may be administered together orseparately and, when administered separately, administration may occursimultaneously or sequentially, in any order. The amounts of thecompound(s) of the present invention and pharmaceutically acceptablesalts or solvates thereof and the other pharmaceutically active agent(s)and the relative timings of administration will be selected in order toachieve the desired combined therapeutic effect. The administration incombination of a compound of the present invention and pharmaceuticallyacceptable salts or solvates thereof with other treatment agents may bein combination by administration concomitantly in a unitarypharmaceutical composition including both compounds, or in separatepharmaceutical compositions each including one of the compounds.Alternatively, the combination may be administered separately in asequential manner wherein one treatment agent is administered first andthe other second or vice versa. Such sequential administration may beclose in time or remote in time.

The present invention may be used in combination with one or more agentsuseful in the prevention or treatment of viral infections. Examples ofsuch agents include; polymerase inhibitors such as those disclosed in WO2004/037818-A1, as well as those disclosed in WO 2004/037818 and WO2006/045613; JTK-003, JTK-019, NM-283, HCV-796, R-803, R1728, R1626, aswell as those disclosed in WO 2006/018725, WO 2004/074270, WO2003/095441, US2005/0176701, WO 2006/020082, WO 2005/080388, WO2004/064925, WO 2004/065367, WO 2003/007945, WO 02/04425, WO2005/014543, WO 2003/000254, EP 1065213, WO 01/47883, WO 2002/057287, WO2002/057245 and similar agents; replication inhibitors such asacyclovir, famciclovir, ganciclovir, cidofovir, lamivudine and similaragents; protease inhibitors such as the HIV protease inhibitorssaquinavir, ritonavir, indinavir, nelfinavir, amprenavir, fosamprenavir,brecanavir, atazanavir, tipranavir, palinavir, lasinavir, and the HCVprotease inhibitors BILN2061, VX-950, SCH503034; and similar agents;nucleoside and nucleotide reverse transcriptase inhibitors such aszidovudine, didanosine, lamivudine, zalcitabine, abacavir, stavidine,adefovir, adefovir dipivoxil, fozivudine, todoxil, emtricitabine,alovudine, amdoxovir, elvucitabine, and similar agents; non-nucleosidereverse transcriptase inhibitors (including an agent havinganti-oxidation activity such as immunocal, oltipraz etc.) such asnevirapine, delavirdine, efavirenz, loviride, immunocal, oltipraz,capravirine, TMC-278, TMC-125, etravirine, and similar agents; entryinhibitors such as enfuvirtide (T-20), T-1249, PRO-542, PRO-140,TNX-355, BMS-806, 5-Helix and similar agents; integrase inhibitors suchas L-870,180 and similar agents; budding inhibitors such as PA-344 andPA-457, and similar agents; chemokine receptor inhibitors such asvicriviroc (Sch-C), Sch-D, TAK779, maraviroc (UK-427,857), TAK449, aswell as those disclosed in WO 02/74769, WO 2004/054974, WO 2004/055012,WO 2004/055010, WO 2004/055016, WO 2004/055011, and WO 2004/054581, andsimilar agents; neuraminidase inhibitors such as zanamivir, oseltamivir,peramivir and similar agents; ion channel blockers such as amantadine orrimantadine and similar agents; and interfering RNA and antisenseoligonucleotides and such as ISIS-14803 and similar agents; antiviralagents of undetermined mechanism of action, for example those disclosedin WO 2005/105761, WO 2003/085375, and WO 2006/122011, and similaragents. The present invention may also be used in combination with oneor more other agents which may be useful in the prevention or treatmentof viral infections for example immune therapies (e.g. interferon orother cytokines/chemokines, cytokine/chemokine receptor modulators,cytokine agonists or antagonists and similar agents); and therapeuticvaccines, antifibrotic agents, anti-inflammatory agents such ascorticosteroids or NSAIDs and similar agents.

The scope of combinations of compounds of this invention andpharmaceutically acceptable salts or solvates thereof with antiviralagents is not limited to those mentioned above, but includes inprinciple any combination with any pharmaceutical composition useful forthe treatment of viral disease. As noted, in such combinations thecompounds of the present invention and pharmaceutically acceptable saltsor solvates thereof and other antiviral agents may be administeredseparately or in conjunction. In addition, one agent may be prior to,concurrent to, or subsequent to the administration of other agent(s).

The compounds of the present invention and pharmaceutically acceptablesalts or solvates thereof may be used in combination with one or moreother agents which may be useful in the prevention or treatment ofallergic disease, inflammatory disease, autoimmune disease or similar,for example; antigen immunotherapy, anti-histamines, steroids,non-steroidal anti-inflammatory agents, bronchodilators (e.g. beta 2agonists, adrenergic agonists, anticholinergic agents, theophylline),methotrexate, leukotriene modulators and similar agents; monoclonalantibody therapy such as anti-IgE, anti-TNF, anti-IL-5, anti-IL-6,anti-IL-12, anti-IL-1 and similar agents; receptor therapies e.g.entanercept and similar agents; antigen non-specific immunotherapies(e.g. interferon or other cytokines/chemokines, cytokine/chemokinereceptor modulators, cytokine agonists or antagonists, TLR agonists andsimilar agents).

The compounds of the present invention and pharmaceutically acceptablesalts or solvates thereof may be used in combination with one or moreother agents which may be useful in the prevention or treatment ofcancer, for example chemotherapeutics such as alkylating agents,topoisomerase inhibitors, antimetabolites, antimitotic agents, kinaseinhibitors and similar agents; monoclonal antibody therapy such astrastuzumab, gemtuzumab and other similar agents; immunotherapies (e.g.interferon or other cytokines/chemokines, cytokine/chemokine receptormodulators, cytokine agonists or antagonists, TLR agonists and similaragents); and hormone therapy such as tamoxifen, goserelin and similaragents.

The pharmaceutical compositions according to the invention may also beused alone or in combination with at least one other therapeutic agentin other therapeutic areas, for example gastrointestinal disease. Thecompositions according to the invention may also be used in combinationwith gene replacement therapy.

The invention includes a combination comprising at least one compound offormula (I), or (a) pharmaceutically acceptable salt(s) or solvate(s)thereof, together with at least one other therapeutically active agent.

The combinations referred to above may conveniently be presented for usein the form of a pharmaceutical formulation and thus pharmaceuticalformulations comprising a combination as defined above together with atleast one pharmaceutically acceptable diluent or carrier thereofrepresent a further aspect of the invention.

A therapeutically effective amount of a compound of the presentinvention or pharmaceutically acceptable salts or solvates thereof willdepend upon a number of factors. For example, the species, age, andweight of the recipient, the precise condition requiring treatment andits severity, the nature of the formulation, and the route ofadministration are all factors to be considered. The therapeuticallyeffective amount ultimately should be at the discretion of the attendantphysician. Regardless, an effective amount of a compound of the presentinvention for the treatment of humans suffering from frailty, generally,should be in the range of 0.01 to 100 mg/kg body weight of recipient(mammal) per day. More usually the effective amount should be in therange of 0.1 to 10 mg/kg body weight per day. Thus, for a 70 kg adultmammal one example of an actual amount per day would usually be from 7to 700 mg. This amount may be given in a single dose per day or in anumber (such as two, three, four, five, or more) of sub-doses per daysuch that the total daily dose is the same. An effective amount of apharmaceutically acceptable salt or solvate of a compound of formula (I)may be determined as a proportion of the effective amount of thecompound of the present invention per se. Similar dosages should beappropriate for treatment of the other conditions referred to herein.

Compounds of formula (I) and pharmaceutically acceptable salts orsolvates thereof may also be administered at any appropriate frequencye.g. 1-7 times per week. The precise dosing regimen will of coursedepend on factors such as the therapeutic indication, the age andcondition of the patient, and the particular route of administrationchosen.

Pharmaceutical formulations may be presented in unit-dose formscontaining a predetermined amount of active ingredient per unit dose.Such a unit may contain, as a non-limiting example, 0.5 mg to 1 g of acompound of formula (I) or pharmaceutically acceptable salts or solvatesthereof, depending on the condition being treated, the route ofadministration, and the age, weight, and condition of the patient.Preferred unit-dosage formulations are those containing a daily dose orsub-dose, as herein above recited, or an appropriate fraction thereof,of an active ingredient. Such pharmaceutical formulations may beprepared by any of the methods well-known in the pharmacy art.

There is thus further provided a pharmaceutical composition comprising acompound of formula (I), or a pharmaceutically acceptable salt orsolvate thereof, and optionally one or more pharmaceutically acceptablediluents or carriers.

There is also provided a process for preparing such a pharmaceuticalcomposition which comprises admixing a compound of formula (I), or apharmaceutically acceptable salt or solvate thereof, with one or morepharmaceutically acceptable diluents or carriers.

Throughout the description and the claims which follow, unless thecontext requires otherwise, the word ‘comprise’, and variations such as‘comprises’ and ‘comprising’, will be understood to imply the inclusionof a stated integer or step or group of integers but not to theexclusion of any other integer or step or group of integers or steps.

The compounds of formula (I) and salts and solvates thereof may beprepared by the methodology described hereinafter, constituting furtheraspects of this invention.

Accordingly, there is provided a process for the preparation of acompound of formula (I), which process comprises the deprotection of acompound of formula (IIA):

wherein R¹ and R² are as hereinbefore defined for a compound of formula(I) and R³ is C₁₋₆alkyl, and thereafter, if required, carrying out oneor more of the following optional steps:(i). converting a compound of formula (I) to a further compound offormula (I);(ii). preparing a salt or solvate of the compound so-formed.

For example, a compound of formula (IIA) is dissolved in a suitablesolvent, for example methanol, and treated with a solution of a suitablemineral acid in a suitable solvent, for example 4N hydrogen chloride in1,4-dioxane. The reaction is stirred at a suitable temperature, forexample room temperature, for a suitable period of time, for example4-18 hours, and the solvent removed under reduced pressure to give amaterial that is then suspended in water. A sufficient amount of asuitable alcohol, for example methanol, may be added until a solution isobtained. A suitable aqueous base, for example 2N sodium hydroxidesolution, is added to bring the mixture to pH7, and the solution may beconcentrated until a suspension is formed. The solid is then filteredand washed with water before being dried to give a compound of formula(I). Alternatively, the reaction mixture may be neutralised withoutprior removal of the solvent, and the resultant product recovered byfiltration before or after removal of a proportion of the solvent.

A compound of formula (IIA) may be prepared by reaction of a compound offormula (II):

wherein R¹ is as hereinbefore defined for a compound of formula (I) andR³ is as hereinbefore defined for a compound of formula (IIA), with acompound of formula (IIB):

R²-L  (IIB)

wherein R² is as hereinbefore defined for a compound of formula (I) andL is a suitable leaving group, for example an alkylsulphonyloxy groupsuch as a methanesulphonyloxy group, or a halogen atom, such as bromine.

For example, the trifluoroacetate salt of a compound of formula (II) isheated to a suitable temperature, for example 60° C., for a suitableperiod of time, for example 1 hour, with anhydrous potassium carbonatein a suitable dry solvent, for example dry DMF, and allowed to cool toroom temperature before adding a compound of formula (IIB). The reactionmay be stirred at room temperature for a suitable period of time, forexample 20-40 hours, and may be heated if necessary for a suitableperiod of time, for example 1-2 hours, at a suitable temperature, forexample up to 90° C. The reaction mixture is poured into water andextracted into a suitable solvent, for example ethyl acetate. Thesolvent extracts are dried, evaporated to dryness under reducedpressure, and purified. It will be appreciated that the reaction timesand reaction temperatures required to effect the reaction of a compoundof formula (II) with a compound of formula (IIB) to give a compound offormula (IIA) will vary depending on the precise nature of theindividual reactants used, for example reaction times and reactiontemperatures must be chosen to ensure that a compound of formula (IIA)is obtained, but that N-alkylation at the 7-position is minimised oravoided.

A compound of formula (II) may be used in the form of a salt, forexample the trifluoroacetate salt. This salt results from thedeprotection of a compound of formula (III) with, for example,trifluoroacetic acid, as hereinbelow described.

Alternatively, a compound of formula (I) may be prepared by reaction ofa compound of formula (II) as hereinbefore defined, typically as a salt,for example the trifluoroacetate salt, with a compound of formula (IIB)as hereinbefore defined, without isolation of the intermediate compound(IIA).

For example, to the trifluoroacetate salt of a compound of formula (II)in a suitable solvent, for example dry N,N-dimethyl formamide (DMF), isadded a suitable base, for example anhydrous potassium carbonate. Themixture is heated to a suitable temperature, for example 60° C., for asuitable period of time, for example 1 hour, and cooled to roomtemperature. A compound of formula (IIB) is then added and the reactionmixture heated to a suitable temperature, for example 50° C., for asuitable period of time, for example 12-18 hours. The reaction isquenched with water and extracted with a suitable solvent, for exampleethyl acetate. The organic phase is separated and dried. Evaporation ofthe organic phase and purification of the oil so formed yields a productwhich is then dissolved in a suitable solvent, for example methanol,treated with a solution of a suitable mineral acid in a suitablesolvent, for example 4N hydrogen chloride in 1,4-dioxane, and stirredovernight at room temperature. The reaction mixture is evaporated todryness under reduced pressure to give a compound of formula (I), whichmay be purified. It will be appreciated that the reaction times andreaction temperatures required to effect the reaction of atrifluoroacetate salt of a compound of formula (II) with a compound offormula (IIB) to give a compound of formula (IIA) will vary depending onthe precise nature of the individual reactants used, for examplereaction times and reaction temperatures must be chosen to ensure that acompound of formula (IIA) is obtained, but that N-alkylation at the7-position is minimised or avoided.

A compound of formula (II) may be prepared by reaction of a compound offormula (III):

wherein R¹ is as hereinbefore defined for a compound of formula (I), Pis a protecting group, typically a tetrahydro-2H-pyran-2-yl group, andR³ is as hereinbefore defined for a compound of formula (IIA), with asuitable deprotecting agent, for example trifluoroacetic acid (the useof trifluoroacetic acid results in a compound of formula (II) beingformed as a trifluoroacetate salt).

For example, to a solution of a compound of formula (III) in a suitablesolvent, for example dry methanol, is added a suitable deprotectingagent, for example trifluoroacetic acid. The mixture is stirred at asuitable temperature, for example ambient temperature, for 24-48 hours.The reaction mixture is concentrated to a slurry before being dilutedwith a suitable solvent, for example ethyl acetate. The slurry isfiltered and washed with a small volume of solvent, for example ethylacetate, until the filtrate is colourless. The solid remaining is driedby air and then in vacuo to give, in the case where trifluoroacetic acidis used as the deprotecting agent, the trifluoroacetate salt of acompound of formula (II). The filtrate obtained previously may beconcentrated to give a slurry which is then diluted with a small volumeof solvent, for example ethyl acetate and then filtered and dried toyield a second crop of the trifluoroacetate salt of a compound offormula (II). Alternatively, the reaction mixture may be concentratedunder reduced pressure to yield a solid, which solid may then betriturated in the presence of a suitable solvent, for example diethylether.

A compound of formula (IIB) wherein L is a halogen atom may be preparedby reaction of a compound of formula (IX):

R²—OG  (IX)

wherein R² is as hereinbefore defined for a compound of formula (I) andOG is a leaving group, for example an alkanesulphonate group such as amethanesulphonate group, with an anhydrous alkali metal halide such asanhydrous lithium bromide.

For example, a compound of formula (IX) and a suitable halogenatingagent, for example anhydrous lithium bromide, in a suitable solvent, forexample, acetone, are refluxed with stirring for a suitable period oftime, for example 3 hours. After allowing to cool the solvent is removedunder reduced pressure, the residue treated with water, and extractedwith a suitable solvent, for example dichloromethane. The combinedsolvent extracts are washed, dried, and the solvent removed underreduced pressure to give a compound of formula (IIB).

A compound of formula (IX), or a compound of formula (IIB) wherein L isan alkylsulphonyl group, may be prepared by reaction of a compound offormula (X):

R²—OH  (X)

wherein R² is as hereinbefore defined for a compound of formula (I),with a suitable activating agent, for example an alkylsulphonyl halidesuch as methanesulphonyl chloride.

For example, to an ice-cooled stirring solution of a compound of formula(X) and a suitable base, for example triethylamine, in a suitable drysolvent, for example dry dichloromethane, is added, dropwise, a suitableactivating agent, for example methanesulphonyl chloride. The mixture isallowed to warm slowly to ambient temperature over a suitable period oftime, for example 16 hours, then washed with saturated sodium hydrogencarbonate. The aqueous layer is further extracted with a suitableorganic solvent, for example dichloromethane, and the organic extractswashed, dried, and the solvent removed under reduced pressure to give acompound of formula (IX).

A compound of formula (X) may be prepared by reaction of a compound offormula (XI):

Het-(CH₂)_((n-1))—COOC₁₋₆alkyl  (XI)

wherein Het and n are as hereinbefore defined for a compound of formula(I) with a suitable reducing agent, such as lithium aluminium hydride.

For example, a stirring solution of a compound of formula (XI) in asuitable dry solvent, for example dry tetrahydrofuran, is cooled, forexample using an ice-bath, and a solution of lithium aluminium hydridein a suitable solvent, for example dry tetrahydrofuran, added dropwiseunder a suitable atmosphere, for example an atmosphere of nitrogen, at asuitable temperature, for example less than 15° C. The reaction isallowed to warm to ambient temperature and, after a suitable period oftime, for example 3 hours, re-cooled using, for example, an ice-bath,and a suitable base, for example 5N sodium hydroxide added whilemaintaining a suitable temperature, for example less than 10° C. Asuitable organic solvent, for example diethyl ether, is then added andthe resulting solid filtered and washed with further organic solvent,for example diethyl ether. The combined filtrate is then evaporated togive a compound of formula (X).

A compound of formula (X) wherein Het is 3-tetrahydropyranyl and n is aninteger having a value of 2 may be prepared by reaction of the compoundof formula (XII):

Het-(CH₂)—CHO  (XII)

wherein Het is 3-tetrahydropyranyl, with a suitable reducing agent, forexample sodium borohydride.

For example, a suspension of a suitable reducing agent, for examplesodium borohydride, in a suitable solvent, for example ethanol, iscooled, for example using an ice-bath, and a solution of the compound offormula (XII) in a suitable solvent, for example ethanol added dropwisewith stirring over a suitable period of time, for example 10 minutes.After a suitable period of time, for example 15 minutes, the ice-bath isremoved and after a further period of time, for example 3 hours, themixture is heated at a suitable temperature, for example 50° C. for asuitable period of time, for example 1 hour. After cooling, the solventis evaporated and the residue treated with water and extracted with asuitable organic solvent, for example dichloromethane. The combinedextracts were washed, dried, and evaporated to give the compound offormula (X) wherein Het is 3-tetrahydropyranyl and n is an integerhaving a value of 2.

The compound of formula (XII) may be prepared by reaction of a compoundof formula (XIII):

Het-CH═CH(OC₁₋₆alkyl)  (XIII)

wherein Het is 3-tetrahydropyranyl, with a suitable mineral acid, forexample hydrochloric acid.

For example, to a stirring solution of a compound of formula (XIII) in asuitable solvent, for example tetrahydrofuran, is added a suitablemineral acid, for example 2N hydrochloric acid. After a suitable periodof time, for example 1 hour, the mixture is diluted with water andextracted with a suitable organic solvent, for example ether. Theorganic extract is then washed, dried, and evaporated to give thecompound of formula (XII).

A compound of formula (XIII) may be prepared by reaction of the compoundof formula (XIV):

Het-CHO  (XIV)

wherein Het is 3-tetrahydropyranyl, with a compound of formula (XV):

C₁₋₆alkoxy-(CH₂)—P⁺(Ph)₃Cl⁻  (XV)

For example, a suspension of a compound of formula (XV) in a suitabledry solvent, for example dry tetrahydrofuran, is cooled to a suitabletemperature, for example minus 40° C. using, for example, a cooling bathcontaining a mixture of dry ice and acetone, and a solution of asuitable strong base, for example potassium tert-butoxide in a suitabledry solvent, for example dry tetrahydrofuran, added dropwise withstirring under a suitable atmosphere, for example an atmosphere ofnitrogen. After a suitable period of time, for example, 45 minutes, themixture is further cooled to minus 65° C. using, for example, a coolingbath containing a mixture of dry ice and acetone, and a solution of thecompound of formula (XIV) in a suitable dry solvent, for example drytetrahydrofuran is added dropwise. The cooling bath is removed and thereaction mixture allowed to warm to ambient temperature. The reactionmixture is then stirred for a further period of time, for example 30minutes, and then quenched by pouring onto ice. The mixture is thenextracted with a suitable solvent, for example ether, and the combinedextracts washed, dried and evaporated to give a crude compound offormula (XIII), which may be purified by, for example, chromatography.

The compound of formula (XIV) may be prepared by hydrogenation of thecompound of formula (XVI):

For example, the compound of formula (XVI) in a suitable solvent, forexample ethanol, is treated with 10% wetted palladium on carbon catalystunder a suitable atmosphere, for example an atmosphere of nitrogen, thenhydrogenated at ambient temperature and pressure for a suitable periodof time, for example 30 minutes. The catalyst removed by filtration andthe filtrate evaporated to give the compound of formula (XIV).

The compound of formula (XVI) may be prepared from acrolein.

For example, concentrated hydrochloric acid is added to water followedby acrolein and a suitable solvent, for example toluene. The stirredmixture is heated under reflux at 75° C. for a suitable period of time,for example 1 hour when reflux will gradually abate. After allowing tocool, a suitable base, for example potassium carbonate, is added untilthe mixture is basic and the mixture extracted with a suitable organicsolvent, for example diethyl ether. The organic extracts are washed withbrine, dried, and evaporated to yield a crude product. The compound offormula (XVI) is obtained from the crude mixture by distillation.

A compound of formula (III) may be prepared by reaction of a compound offormula (IV):

wherein R¹ is as hereinbefore defined for a compound of formula (I), Pis as hereinbefore defined for a compound of formula (III), and X is ahalogen atom, for example bromine, with an alkali metal alkoxide, forexample sodium methoxide.

For example, a compound of formula (IV) is heated to a suitabletemperature, for example to reflux temperature to or just below refluxtemperature, with an alcoholic solution of an alkali metal alkoxide, forexample 25% sodium methoxide in methanol, in a suitable solvent, forexample methanol, for a suitable period of time, for example 2-8 hours.The reaction mixture is concentrated under reduced pressure andpartitioned between suitable aqueous and non-aqueous phases, for exampleethyl acetate and saturated ammonium chloride solution. The organicphase is separated and the aqueous phase extracted repeatedly into ethylacetate. The combined organic phases are washed, dried, evaporated, andthen placed under reduced pressure to give a compound of formula (III).

A compound of formula (IV) may be prepared by reaction of a compound offormula (V):

wherein R¹ is as hereinbefore defined for a compound of formula (I) andP is as hereinbefore defined for a compound of formula (III), with asuitable halogenating agent, for example N-bromosuccinimide.

For example, a compound of formula (V) is dissolved in a suitablesolvent, for example chloroform, and cooled to a suitable temperature,for example 0° C. To this solution is added portionwiseN-bromosuccinimide, whilst maintaining a suitable temperature, forexample less than 3° C. The resulting mixture is stirred at a suitabletemperature, for example 2-3° C., for a suitable period of time, forexample 30 minutes, before allowing to warm to room temperature and thenstirring for a further period of time, for example 6 hours. The reactionmixture is then washed with water. The organic phase is dried/separatedusing a hydrophobic frit and evaporated to give a crude compound offormula (IV), which may be purified.

A compound of formula (V), wherein R¹ is C₁₋₈alkoxy,C₃₋₇cycloalkylC₁₋₆alkoxy, C₁₋₆alkoxyC₁₋₆alkoxy, or Het^(b)-C₁₋₃alkoxy,may be prepared by reaction of a compound of formula (VI):

wherein P is as hereinbefore defined for a compound of formula (III) andY is a halogen atom, for example chlorine, with a compound of formula(VIA):

R¹—H  (VIA)

wherein R¹ is C₁₋₈alkoxy, C₃₋₇cycloalkylC₁₋₆alkoxy,C₁₋₆alkoxyC₁₋₆alkoxy, or Het^(b)-C₁₋₃alkoxy, in the presence of a strongbase of appropriate strength, for example sodium metal, sodium hydride,or sodium tert-butoxide.

For example, to a compound of formula (VIA), for example butan-1-ol, isadded portion-wise a strong base, for example sodium tert-butoxide. Themixture is stirred until homogeneous before a compound of formula (VI)is added to the solution. The reaction mixture is then heated to asuitable temperature, for example 100° C., for a suitable period oftime, for example 12-18 hours. The reaction mixture is placed underreduced pressure to remove as much of a compound of formula (VIA) aspossible before being partitioned between a suitable organic solvent,for example diethyl ether, and water. The organic phase is separated andthe aqueous phase may be re-extracted with further organic solvent. Thecombined organic phases are dried over a suitable drying agent, forexample anhydrous magnesium sulphate. The drying agent is removed byfiltration and the filtrate evaporated under reduced pressure to give acompound of formula (V) wherein R¹ is C₁₋₆alkoxy, which may then befurther treated by, for example, being azeotroped with toluene andplaced under reduced pressure.

A compound of formula (V), wherein R¹ is C₁₋₈alkylamino orC₃₋₇cycloalkylC₁₋₆alkylamino may be prepared by reaction of a compoundof formula (VI) as hereinbefore defined, with a compound of formula(VIB):

R¹—H  (VIB)

wherein R¹ is C₁₋₆alkylamino or C₃₋₇cycloalkylC₁₋₆-amino.

For example, to a solution of a compound of formula (VI) in a suitabledry solvent, for example dry ethylene glycol, at a suitable temperature,for example room temperature, and under a suitable atmosphere, forexample an atmosphere of nitrogen, is added a compound of formula (VIB).The reaction is heated at a suitable temperature, for example 120° C.,for a suitable period of time, for example 12-18 hours. The reaction iscooled to room temperature, diluted with a suitable solvent, for exampleethyl acetate, and washed with water. The organic layer is dried over asuitable drying agent, for example anhydrous magnesium sulphate,filtered and concentrated in vacuo to afford a compound of formula (V)wherein R¹ is C₁₋₆alkylamino.

A compound of formula (VI) may be prepared by reaction of a compound offormula (VII):

wherein P is as hereinbefore defined for a compound of formula (III), Yis as hereinbefore defined for a compound of formula (VI), and Z is ahalogen atom, for example chlorine, with an alcoholic solution ofammonia.

For example, a compound of formula (VII) is heated with 2M solution ofammonia in a suitable alcohol, for example, iso-propyl alcohol, at asuitable temperature, for example 50° C., for a suitable period of time,for example 5 hours. After standing at ambient temperature for asuitable period of time, for example 12-18 hours, a further quantity ofthe alcoholic ammonia is added to break up the resultant cake and thereaction mixture heated for a further suitable period of time, forexample 9 hours, until the reaction is complete. To the reaction mixtureis added water and the solid product filtered off. The solid is thenwashed, for example with a mixture of iso-propyl alcohol and water, andthen air-dried under suction to give a first crop. The filtrate may bere-filtered after standing for 12-18 hours to afford a second crop andthe crops then dried in vacuo.

A compound of formula (VII) may be prepared from a compound of formula(VIII):

wherein Y is as hereinbefore defined for a compound of formula (VI) andZ is as hereinbefore defined for a compound of formula (VII), byreaction with a suitable protecting reagent, for example3,4-dihydro-2H-pyran.

For example, a compound of formula (VIII) is added a suitable solvent,for example ethyl acetate, followed by p-toluenesulfonic acid. Themixture is heated to a suitable temperature, for example 50° C., andthen 3,4-dihydro-2H-pyran added. The reaction mixture is then heated ata suitable temperature, for example 50° C., for a suitable period oftime, for example 4 hours. The reaction mixture is then evaporated invacuo to give a compound of formula (VII).

The present invention includes a process for the preparation of acompound of formula (I), which process comprises the hydrolysis of acompound of formula (XXI):

wherein R¹ and R² are as hereinbefore defined for a compound of formula(I) and X is as hereinbefore defined for a compound of formula (IV).

For example, to a solution of a compound of formula (XXI) in a suitablesolvent, for example dry n-butanol, is added a suitable concentratedmineral acid, for example concentrated hydrochloric acid at a suitabletemperature, for example ambient temperature. The reaction is thenheated to a suitable temperature, for example 80-120° C. for a suitableperiod of time, for example 0.5-8 hours. The volume of the reactionmixture is then was reduced, for example by concentration in vacuo,water added, and the mixture neutralised by the addition of a suitableaqueous base, for example sodium hydroxide solution. The product is thenisolated and purified by conventional means, for example the product maybe isolated by filtration and purified by chromatography.

A compound of formula (XXI) may be prepared by halogenation of acompound of formula (XX):

wherein R¹ and R² are as hereinbefore defined for a compound of formula(I).

When R¹ is C₁₋₈alkylamino or C₃₋₇cycloalkylC₁₋₆alkylamino, thehalogenation of a compound of formula (XX) may be undertaken, forexample, as follows:

To a solution of a compound of formula (XX) in a suitable dry solvent,for example dry chloroform, at a suitable temperature, for exampleambient temperature is added N-bromosuccinimide. The reaction mixture isstirred at a suitable temperature, for example ambient temperature, fora suitable period of time, for example one hour. The reaction mixture isthen diluted with a suitable solvent, for example dichloromethane, andwashed with water. The organic phase is then dried, for example bypassage through a hydrophobic frit, and concentrated.

When R¹ is C₁₋₈alkoxy, C₃₋₇cycloalkylC₁₋₆alkoxy, C₁₋₃alkoxyC₂₋₃alkoxy,or Het^(b)-C₁₋₃alkoxy, the halogenation of a compound of formula (XX)may be undertaken, for example, as follows:

A compound of formula (XX) is dissolved in glacial acetic acid beforeadding sodium acetate. The mixture is then cooled to a suitabletemperature, for example in an ice-bath, and bromine gradually added.The reaction mixture is warmed to a suitable temperature, for exampleambient temperature, before being heated to a suitable temperature, forexample in a heating device set to a temperature of 60-80° C. for asuitable period of time, for example 3-6 hours. The reaction mixture isquenched with sodium thiosulphate solution and then the pH adjusted to6-7 by the addition of a suitable base, for example aqueous sodiumhydroxide solution. The mixture is then extracted into a suitableorganic solvent, for example ethyl acetate, the organic layer separated,dried, and the solvent removed.

A compound of formula (XX), wherein R¹ is C₁₋₈alkoxy,C₃₋₇cycloalkylC₁₋₆alkoxy, C₁₋₆alkoxyC₁₋₆alkoxy, or Het^(b)-C₁₋₃alkoxymay be prepared by reaction of a compound of formula (XIX):

wherein Y is as hereinbefore defined for a compound of formula (VI) andR² is as hereinbefore defined for a compound of formula (I), with acompound of formula (VIA) as hereinbefore defined.

For example, a compound of formula (XIX) is added to a suspension of acompound of formula (VIA) and a strong base, for example sodiumtert-butoxide. The reaction mixture is then heated, for example in amicrowave oven, for a suitable period of time, for example 20-45 minutesat a suitable temperature, for example 90-120° C. The reaction mixtureis then diluted with a suitable solvent, for example ethyl acetate, andwashed with water. The organic phase is separated and dried, for exampleby passage through a hydrophobic frit, and concentrated. The compound offormula (XX) may be isolated by conventional means, for exampletrituration followed by filtration.

A compound of formula (XX), wherein R¹ is C₁₋₈alkylamino,C₃₋₇cycloalkylC₁₋₆alkylamino, may be prepared by reaction of a compoundof formula (XIX) with a compound of formula (VIB) as hereinbeforedefined.

For example, a solution of a compound of formula (XIX) in a suitablesolvent, for example cyclohexylamine, is heated, for example in amicrowave oven, at a suitable temperature, for example 150-180° C., fora suitable period of time, for example five minutes. The crude reactionmixture is then purified by, for example chromatography.

A compound of formula (XIX) may be prepared by reaction of a compound offormula (XVIII):

wherein Y is as hereinbefore defined for a compound of formula (VI), Zis as hereinbefore defined for a compound of formula (VII), and R² is ashereinbefore defined for a compound of formula (I), with ammonia.

For example, a compound of formula (XVIII) (which may contain residualtriphenylphosphine oxide as an impurity from the synthesis of a compoundof formula (XVIII), is heated with an alcoholic solution of ammonia, forexample 2M ammonia in iso-propyl alcohol, at a suitable temperature, forexample 40-60° C., for a suitable period of time, for example 12-18hours. The reaction mixture is then evaporated to dryness and theproduct purified by recrystallisation from a suitable solvent, forexample methanol.

A compound of formula (XIX) may also be prepared by reaction of acompound of formula (XVII):

wherein Y is as hereinbefore defined for a compound of formula (VI),with a compound of formula (IIB) as hereinbefore defined.

For example, to a suspension of a compound of formula (XVII) and asuitable base, for example potassium carbonate, in a suitable solvent,for example N,N-dimethylformamide, is added a compound of formula (IIB).The mixture is stirred at a suitable temperature, for example 80-100°C., for a suitable period of time, for example 12-18 hours. The reactionmixture is then taken up in a suitable solvent, for example a mixture ofchloroform and iso-propyl alcohol and extracted with water. The organicphase is then separated, dried by, for example passage through ahydrophobic frit, and concentrated.

A compound of formula (XVIII) may be prepared by reaction of a compoundof formula (VIII) as hereinbefore defined with a compound of formulaR²—OH, wherein R² is as hereinbefore defined for a compound of formula(I).

For example, a mixture of a compound of formula (VIII) and a compound offormula R²—OH is dissolved in a suitable dry solvent, for example drytetrahydrofuran. To this solution is added triphenylphosphine, followedby diisopropyl azodicarboxylate (dropwise). The temperature of thereaction mixture is kept below about 45° C. by cooling, for example witha water-bath. The reaction mixture is then stirred for a suitable periodof time, for example 12-18 hours, at a suitable temperature, for exampleambient temperature, quenched with water, and extracted into a suitableorganic solvent, for example ethyl acetate. The organic phase isseparated, washed with water, and then dried by, for example, passagethrough a hydrophobic frit, and concentrated under reduced pressure. Thecrude product may be purified by conventional means, for examplechromatography.

A compound of formula (XVII) may be prepared by reaction of a compoundof formula (VIII) as hereinbefore defined with ammonia.

For example, a mixture of a compound of formula (VIII) and ammoniasolution in a suitable solvent, for example iso-propyl alcohol, isstirred and heated at a suitable temperature, for example 100-140° C. inan autoclave for a suitable period of time, for example 12-18 hours. Thereaction is then cooled and concentrated to give a compound of formula(XVII).

The present invention includes a synthetic process for, a compound offormula (I), wherein R¹ is C₁₋₈alkylamino orC₃₋₇cycloalkylC₁₋₆alkylamino, which may be prepared by reaction of acompound of formula (XXIII):

wherein Y is as hereinbefore defined for a compound of formula (VI), R²is as hereinbefore defined for a compound of formula (I), and R³ is ashereinbefore defined for a compound of formula (IIA), with a compound offormula (VIB) as hereinbefore defined.

For example, a mixture of a compound of formula (XXIII) and a compoundof formula (VIB) is heated, for example in a microwave oven, at asuitable temperature, for example 150-190° C. for a suitable period oftime, for example 10-20 minutes. The reaction mixture is thenconcentrated to yield a crude product which is purified by conventionalmeans, for example chromatography.

A compound of formula (XXIII) may be prepared by reaction of a compoundof formula (XXII):

wherein X is as hereinbefore defined for a compound of formula (IV), Yis as hereinbefore defined for a compound of formula (VI) and R² is ashereinbefore defined for a compound of formula (I), with a source ofalkoxide anion.

For example, a solution of a compound of formula (XXII) in a suitablesolvent, for example dry methanol, was added a suitable base, forexample aqueous sodium hydroxide solution and the mixture was stirred atreflux for a suitable period of time, for example 15-45 minutes. Thereaction mixture is cooled to a suitable temperature, for exampleambient temperature, and concentrated. The residue obtained istriturated with water and extracted with a suitable solvent, for exampleethyl acetate. The organic layer is separated, washed, dried, filteredand concentrated to give a solid product which may be purified byconventional means, for example chromatography.

A compound of formula (XXII) may be prepared by reaction of a compoundof formula (XIX) as hereinbefore defined, with a halogenating agent.

For example, a solution of a compound of formula (XIX) in a suitable drysolvent, for example chloroform, at a suitable temperature, for exampleambient temperature, is added a suitable halogenating agent, for exampleN-bromosuccinimide. The reaction mixture is stirred at a suitabletemperature, for example 50-70° C. for a suitable period of time, forexample 5-7 hours. The reaction mixture is cooled, for example toambient temperature, taken up in a suitable solvent, for exampledichloromethane, and washed with water. The organic phase is then driedby, for example passage through a hydrophobic frit, and concentrated.

ABBREVIATIONS

The following list provides definitions of certain abbreviations as usedherein. It will be appreciated that the list is not exhaustive, but themeaning of those abbreviations not hereinbelow defined will be readilyapparent to those skilled in the art.

DCM Dichloromethane DME 1,2-Dimethoxyethane DMF N,N-DimethylformamideEtOAc Ethyl acetate Et₂O Diethyl ether h hours HCl Hydrochloric acidHPLC High performance liquid chromatography ISCO Automated flashchromatography equipment with Companion fraction analysis by UVabsorption available from Presearch Limited, Basingstoke, Hants., RG248PZ, UK MDAP HPLC Reverse phase HPLC on a C₁₈ column using a two-solventgradient elution with (A) water containing formic acid (0.1%) and (B)acetonitrile-water (95:5 v/v) containing formic acid (0.05%) as theeluents, and analysis of the fractions by electrospray massspectroscopy. MeOH Methanol mins minutes NBS N-Bromosuccinimide StrippedRemoval of solvent under reduced pressure TBME Tertiary butyl methylether TFA Trifluoroacetic acid iPr iso-Propyl t-Bu tert-Butyl Ms MesylAc Acetyl n-Bu n-Butyl Ph Phenyl

The synthetic processes hereinbefore described are summarised in Scheme1.

Typical reaction conditions for each of the synthetic steps of Scheme 1are provided below:

-   A Dihydropyran/paratoluene sulphonic acid, e.g. 50° C. for 4 hours.-   B Ammonia/iPrOH, e.g. 50° C. for 5 hours, then ambient temperature    for 12-18 hours, then 50° C. for 9 hours; or 60° C. for 4 hours.-   C For X═NH:— R^(A)NH₂/ethylene glycol e.g. 120° C. for 12-18 hours.    -   For X═O:— R^(A)OH/KOtBu/dimethoxyethane e.g. 93-110° C. for        12-18 hours. R^(A)OH/KOtBu or NaH e.g. 50° C. for 72 hours; or        12-18 hours, then 72 hours, or 80-90° C. for 2-4 hours, or        100° C. for 12-18 hours.-   D NBS in CH₂Cl₂ or CHCl₃ e.g. 0-20° C. for 10 minutes to 6.5 hours,    or ambient temperature for 0.25-2 hours.-   E NaOMe/MeOH e.g. reflux 1-18 hours or 60° C. for 12-48 hours.-   F TFA/MeOH e.g. ambient temperature for 18-65 hours.-   G K₂CO₃/DMF then R²L where L=halogen-Br e.g. 60° C. for 1-1.5 hours,    then;    -   a) 50° C. for 2-18 hours, or;    -   b) 60° C. for 2-16 hours, or;    -   c) 50° C. for 12-18 hours, then 70° C. for 8 hours, or;    -   d) ambient temperature for 39 hours then 50° C. for 2 hours, or    -   e) 50° C. for 12-18 hours then 70° C. for 8 hours, or;    -   f) 50° C. for 12-18 hours, then 90° C. for 2 hours.    -   or where L=OMs e.g. 60° C. for 1-1.5 hours then;    -   a) 90° C. for 2-3.5 hours, or;    -   b) 50° C. 5 h, ambient temperature 16 hours, LiBr at 90° C. for        8 hours, or;    -   c) 60° C. for 3-16 hours.-   H HCl/1,4-dioxane e.g. ambient temperature for 1-18 hours.-   I Ammonia/iPrOH e.g. 120° C. for 12-18 hours.-   J K₂CO₃/DMF then R²L where L=halogen, for example 90° C. for 12-18    hours.-   K X═O: R¹OH/KOtBu e.g. 30 mins. At 105° C. in a microwave oven.    -   X═NH: R¹NH₂ e.g. 170° C. in microwave oven for 2-5 min.-   L X═O: Br₂/AcOH e.g. ice-bath-ambient temperature then 70° C. for 4    hours.    -   X═NH: NBS in CHCl₃ e.g. ambient temperature for 40 min-1 hour.-   M R²OH/PPh₃/diisopropyl azodicarboxylate e.g. ambient temperature    −43° C.-   N Ammonia/iPrOH e.g. 50° C. for 12-18 hours.-   O NBS in CHCl₃ e.g. 60° C. for 6 hours.-   P NaOH MeOH e.g. reflux 0.5 hours.-   Q R¹NH₂ neat e.g. 170° C. in microwave oven for 10-15 mins.    -   R¹NH₂/ethylene glycol e.g. 170° C. in microwave oven for 2×30        min. then 180° C. in microwave oven for 30 min.-   R c.HCl/nBuOH e.g. 100° C. for 0.5-6 hours.

Compounds of formulae (VIA), (VIB), (VIII), (X), (XI), (XII), (XIII),(XIV), XV), (XVI), and acrolein are commercially available and may beobtained from, for example, Sigma-Aldrich, UK; TCI Europe, Belgium; ABCRGmbH & Co. KG, Germany; Pharma Core Inc., USA; Chemical Block Ltd.,Russia; Lancaster Synthesis (Alfa Aesar), UK, or may be prepared byanalogy with known procedures, for example those disclosed in standardreference texts of synthetic methodology such as J. March, AdvancedOrganic Chemistry, 4th Edition (1992), Wiley Interscience, orComprehensive Organic Synthesis (Trost B. M. and Fleming I., (Eds.),Pergamon Press, 1991), each incorporated herein by reference as itrelates to such procedures.

Examples of other protecting groups that may be employed in thesynthetic routes described herein and the means for their removal can befound in T. W. Greene ‘Protective Groups in Organic Synthesis’, 3rdedition, J. Wiley and Sons, 1999, incorporated herein by reference as itrelates to such procedures.

For any of the hereinbefore described reactions or processes,conventional methods of heating and cooling may be employed, for exampletemperature-regulated oil-baths or temperature-regulated hot-blocks, andice/salt baths or dry ice/acetone baths respectively. Conventionalmethods of isolation, for example extraction from or into aqueous ornon-aqueous solvents may be used. Conventional methods of drying organicsolvents, solutions, or extracts, such as shaking with magnesiumsulphate, or sodium sulphate, or passing through a hydrophobic frit, maybe employed. Conventional methods of purification, for examplecrystallisation and chromatography, for example silica chromatography orreverse-phase chromatography, may be used as required. Crystallisationmay be performed using conventional solvents such as methanol, ethanol,or butanol, or aqueous mixtures thereof. It will be appreciated thatspecific reaction times temperatures may typically be determined byreaction-monitoring techniques, for example thin-layer chromatographyand LC-MS.

Where appropriate individual isomeric forms of the compounds of formula(I) may be prepared as individual isomers using conventional proceduressuch as the fractional crystallisation of diastereoisomeric derivativesor chiral high performance liquid chromatography (chiral HPLC).

The absolute stereochemistry of compounds may be determined usingconventional methods, such as X-ray crystallography.

The invention is illustrated by reference to, but is in no way limitedby, the following Examples.

Experimental Details

Experimental details of LCMS systems A and B as referred to herein areas follows:

System A

Column: 3.3 cm×4.6 mm ID, 3 μm ABZ+PLUS from SupelcoFlow Rate: 3 mL/min.

Injection Volume: 5 μL Temp: RT UV Detection Range: 215 to 330 nm

Solvents: A: 0.1% formic acid+10 mM ammonium acetate

-   -   B: 95% acetonitrile+0.05% formic acid

Gradient: Time (min.) A % B % 0 100 0 0.7 100 0 4.2 0 100 5.3 0 100 5.5100 0

System B

Column: 50 mm×2.1 mm ID, 1.7 μm Acquity HPLC BEH C₁₈Flow Rate: 1 mL/min.

Injection Volume: 0.5 μL Temp: 40° C. UV Detection Range: 220 to 330 nm

Solvents: A: 0.1% formic acid+10 mM ammonium acetate

-   -   B: 95% acetonitrile+0.05% formic acid

Gradient: Time (min.) A % B % 0 97 3 0.7 97 3 4.2 0 100 5.3 0 100 5.5 973

For Intermediates 219-292 and Examples 61-141, chromatographicpurification was undertaken as detailed below.

Chromatographic purification was typically performed using pre-packedsilica gel cartridges. The Flashmaster II is an automated multi-userflash chromatography system, available from Argonaut Technologies Ltd,which utilises disposable, normal phase, Solid Phase Extraction (SPE)cartridges (2 g to 100 g). It provides quaternary on-line solvent mixingto enable gradient methods to be run. Samples are queued using themulti-functional open access software, which manages solvents,flow-rates, gradient profile and collection conditions. The system isequipped with a Knauer variable wavelength UV-detector and two GilsonFC204 fraction-collectors enabling automated peak cutting, collectionand tracking.

For Intermediates 219-292 and Examples 61-141, NMR spectra were recordedas detailed below.

¹H NMR spectra were recorded in either CDCl₃ or DMSO-d₆ on either aBruker DPX 400 or Bruker Avance DRX or Varian Unity 400 spectrometer allworking at 400 MHz. The internal standard used was eithertetramethylsilane or the residual protonated solvent at 7.25 ppm forCDCl₃ or 2.50 ppm for DMSO-d₆.

For Intermediates 219-292, mass-directed autopreparation was undertakenunder the conditions given below.

Mass directed autopreparative HPLC was conducted on an XBridge C18column (100 mm×19 mm i.d. 5 μm packing diameter) at ambient temperature.The solvents employed were:

A=10 mM aqueous Ammonium Bicarbonate adjusted to pH 10 with Ammoniasolution.

B=Acetonitrile.

A flow rate of 20 ml/min was employed. A typical gradient was:

Time (min.) A % B % 0 70 30 1 70 30 10 15 85 11 1 99 15 1 99

The UV detection was an averaged signal from wavelength of 210 nm to 350nm and mass spectra were recorded on a mass spectrometer usingalternate-scan positive and negative mode electrospray ionization.

EXAMPLES Intermediate 1:2,6-Dichloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purine

To 2,6-dichloropurine (25.0 g) was added ethyl acetate (260 mL),followed by p-toluenesulfonic acid (0.253 g). The mixture was heated to50° C. and then 3,4-dihydro-2H-pyran (16.8 g) was added. The reactionmixture was then heated at 50° C. for 4 hours. The reaction mixture wasevaporated in vacuo to give the title compound as a yellow solid (36.9g).

1H NMR (CDCl₃): 8.35 (1H, s), 5.77 (1H, dd), 4.20 (1H, m), 3.79 (1H, m),2.20-1.65 (6H, m).

Intermediate 2: 2-Chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

2,6-Dichloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purine (36.9 g) was heatedwith 2M ammonia in isopropanol (250 mL) at 50° C. for 5 hours. Afterstanding at ambient temperature overnight, a further quantity of 2Mammonia in isopropanol (100 mL) was added to break up the resultant cakeand the reaction mixture was heated for a further 9 hours until thereaction was complete. To the reaction mixture was added water (70 mL)and the yellow solid filtered off. The solid was washed with isopropylalcohol:water (5:1 (v/v), 60 mL) and then air-dried under suction togive a first crop. The filtrate was re-filtered after standing overnightto isolate precipitate and both solids were dried in vacuo. The firstcrop was pure with the second crop material showing a very minorimpurity (isolated broad signal 3.5 ppm not seen in first crop) but wasotherwise identical. Solid first crop (28.4 g), solid second crop (3.42g).

1H NMR (CDCl₃): 8.01 (1H, s), 5.98 (2H, broad s), 5.70 (1H, dd), 4.16(1H, m), 3.78 (1H, m), 2.15-1.60 (6H, overlapping m).

Intermediate 2 (alternative method):2-Chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To a solution of 2,6-dichloropurine (25 g) in dry ethyl acetate (200 ml)was added p-toluenesulfonic acid monohydrate (235 mg). The reaction washeated to 50° C. and 3,4-dihydro-2H-pyran (18.1 ml) was added in one go.The reaction was allowed to stir at 50° C. for 1 hour and the solventwas removed under reduced pressure. This afforded a yellow solid. Asuspension of this solid (˜36 g) in 2.0M ammonia in isopropanol (460 ml)was heated under nitrogen at 60° C. for 4 hours with an attachedcondenser. The reaction was poured into water (50 ml) and left to coolovernight. The precipitate was filtered and dried on a rotary evaporator(60° C.) for 30 minutes to afford the title compound as an off-whitesolid (31 g, 93%, 2 steps).

MS calcd for (C₁₀H₁₂ClN₅O)⁺=254, 256

MS found (electrospray): (M)⁺=254, 256 (3:1)

¹H NMR ((CD₃)₂SO): δ 8.43 (1H, s), 7.82 (2H, s), 5.55 (1H, dd), 4.00(1H, m), 3.69 (1H, m), 2.21 (1H, m), 1.95 (2H, m), 1.74 (1H, m), 1.56(2H, m).

Intermediate 3: 2-(Butoxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To butan-1-ol (76 mL) was added portion wise sodium tert-butoxide (15.2g) (Note: reaction mixture gets warm). The above was stirred untilhomogeneous (˜15 min) before2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (10.0 g) was thenadded to the resultant pale yellow solution. The reaction mixture wasthen heated to 100° C., overnight. The reaction mixture was stripped toremove as much butan-1-ol as possible before being partitioned betweendiethyl ether and water. The diethyl ether phase was separated and theaqueous re-extracted further with diethyl ether. Combined organic layersdried over magnesium sulphate (anhydrous). Magnesium sulphate wasfiltered off and filtrate stripped to give brown viscous oil which wasazeotroped with toluene (3 times) and placed under high vacuumovernight, transferred to new flask with dichloromethane and stripped,placed under high vacuum to give the title compound as a brown glass(9.45 g).

1H NMR (CDCl₃): 7.85 (1H, s), 5.92 (2H, broad s), 5.64 (1H, d), 4.32(2H, t), 4.14 (1H, m), 3.75 (1H, m), 2.10-1.95 (3H, overlapping m),1.81-1.58 (5H, overlapping m), 1.50 (2H, m), 0.97 (3H, t).

Intermediate 4:8-Bromo-2-butoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

2-Butoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (9.45 g) wasdissolved in chloroform (50 mL) and cooled to 0° C. (ice-bath). To thissolution was added portion wise N-bromosuccinimide (6.07 g) keeping thetemperature below 3° C. This gave a dark green solution, stirred at 2.5°C. for 30 minutes before allowing to warm to room temperature and thenstirring for 6 hours. The reaction mixture was then washed with water(100 mL, twice). Organic phase was dried/separated using a hydrophobicfrit and evaporated to give a dark brown gum which was purified bysilica chromatography (120 g) (ISCO) using a gradient elution of 0-50%ethyl acetate:cyclohexane to afford the title compound as a pale yellowsolid (8.37 g).

1H NMR (CDCl₃): 5.61 (1H, dd), 5.49 (2H, broad s), 4.32 (2H, m), 4.17(1H, m), 3.71 (1H, m), 3.04 (1H, m), 2.11 (1H, broad d), 1.89-1.45 (6H,overlapping m), 1.50 (2H, m), 0.97 (3H, t).

Intermediate 5:2-Butoxy-8-methoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

8-Bromo-2-butoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (8.37 g)was heated to reflux with 25% sodium methoxide in methanol (14.4 mL) andmethanol (65 mL) for 4.5 hours. The reaction mixture was concentratedunder reduced pressure and partitioned between ethyl acetate andsaturated ammonium chloride solution. Separated organic phase andrepeated extraction into ethyl acetate. Combined organic phases andwashed with brine (twice). The organic phase was passed through ahydrophobic frit after separating aqueous and was evaporated to give alight brown gum which was placed under high vacuum to give a foam (7.52g) which collapsed to a gum (7.34 g) at ambient pressure and solidifiedovernight to give the title compound as a yellow amorphous solid.

MS calcd for (C₁₅H₂₃N₅O₃)⁺=321

MS found (electrospray): (M+H)⁺=322

1H NMR (CDCl₃): 5.50 (1H, dd), 5.17 (2H, broad s), 4.29 (2H, t), 4.12(3H, s and 1H, m), 3.70 (1H, m), 2.77 (1H, m), 2.05 (1H, m), 1.82-1.63(6H, overlapping m), 1.50 (2H, m), 0.97 (3H, t).

Intermediate 6: 2-Butoxy-8-methoxy-9H-purin-6-amine trifluoroacetatesalt

To a solution of2-butoxy-8-methoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (7.34g) in methanol (100 mL) was added trifluoroacetic acid (10 mL). Themixture was stirred at ambient temperature over the weekend to give asuspension. The reaction mixture was concentrated to a small volume(thick slurry) before being diluted with ethyl acetate (50 mL). Theresultant slurry was filtered and washed with a small volume of ethylacetate until the filtrate was colourless. The solid remaining was driedby air and then in vacuo to give the title compound as a solid (6.20 g).The filtrate obtained previously was concentrated to give a slurry whichwas diluted with a small volume of ethyl acetate (10 mL) and thenfiltered and dried as above. This second crop was isolated as a whitesolid (0.276 g). Both crops were identical by NMR.

MS calcd for (C₁₀H₁₅N₅O₂)⁺=237

MS found (electrospray): (M+H)⁺=238

1H NMR (CD₃OD): 4.47 (2H, t), 4.15 (3H, s), 1.80 (2H, m), 1.50 (2H, m),0.99 (3H, t) (exchangeable NH₂, NH and COOH protons not observed).

Intermediate 7:2-Butoxy-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

2-Butoxy-8-methoxy-9H-purin-6-amine trifluoroacetate salt (0.5 g) washeated to 60° C. for 1 hour with anhydrous potassium carbonate (0.79 g)in dry DMF (10 mL) and allowed to cool to room temperature before adding4-(bromomethyl)tetrahydro-2H-pyran (0.26 g). The reaction was stirred atroom temperature for 39 hours and heated for 2 hours at 50° C. Thereaction was poured into water and extracted into ethyl acetate (twice).The combined ethyl acetate extracts were dried through a hydrophobicfrit, stripped to dryness and purified first by silica chromatography(ISCO) (40 g) eluting with 0-100% ethyl acetate:cyclohexane then 0-20%methanol:ethyl acetate and then by reverse phase chromatography (43 g,C-18) (ISCO) eluting 20-60% acetonitrile (0.05% formic acid):water (0.1%formic acid) to give the title compound as a white solid.

MS calcd for (C₁₆H₂₅N₅O₃)⁺=335

MS found (electrospray): (M+H)⁺=336

1H NMR (CD₃OD): 4.29 (2H, t), 4.13 (3H, s), 3.92 (2H, m), 3.81 (2H, dd),3.36 (2H, m), 2.12 (1H, m), 1.74 (2H, m), 1.52-1.47 (4H, m), 1.37 (2H,m), 0.98 (3H, t) (NH₂ exchanged).

Intermediate 8:2-Butoxy-8-methoxy-9-(tetrahydro-2H-pyran-2-ylmethyl)-9H-purin-6-amine

2-Butoxy-8-methoxy-9H-purin-6-amine trifluoroacetate salt (0.20 g) washeated with anhydrous potassium carbonate (0.315 g) in dry DMF (5 mL) at60° C. for 1 hour and cooled to room temperature.2-(Bromomethyl)tetrahydro-2H-pyran (73 uL) was added and the reactionmixture heated at 50° C., overnight. The reaction mixture was quenchedinto water (50 mL) and extracted into ethyl acetate (25 mL, 3 times).The combined organic layers were separated and passed through ahydrophobic frit to dry, then stripped to dryness and the pale yellowgum (145 mg), which turned to a white solid when triturated withmethanol, was purified by MDAP to give the title compound (6 mg) (˜85%pure).

MS calcd for (C₁₆H₂₅N₅O₃)⁺=335

MS found (electrospray): (M+H)⁺=336.

Intermediate 9:N²-Butyl-9-(tetrahydro-2H-pyran-2-yl)-9H-purine-2,6-diamine

To a solution of 2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(10 g) in dry ethylene glycol (50 ml) at room temperature and undernitrogen was added n-butylamine (16 ml) in one go. The reaction washeated at 120° C. overnight. The reaction was cooled to roomtemperature, diluted with ethyl acetate (150 ml) and washed with water(2×50 ml). The organic layer was dried over MgSO₄, filtered andconcentrated in vacuo. This afforded the title compound as a viscousgreen oil (10.2 g) that was used in the next step without furtherpurification.

MS calcd for (C₁₄H₂₂N₆O)⁺=290

MS found (electrospray): (M+H)⁺=291

¹H NMR ((CD₃)₂SO): δ 7.8 (1H, s), 6.6 (2H, s), 6.2 (1H, t), 5.4 (1H,dd), 4.0 (1H, m), 3.6 (1H, m), 3.2 (2H, m), 2.2 (1H, m), 1.9 (1H, m),1.8 (1H, m), 1.7 (1H, m), 1.5 (2H, m), 1.4 (2H, m), 1.3 (2H, m), 0.9(3H, t).

Intermediate 10: N²-Butyl-8-methoxy-9H-purine-2,6-diaminetrifluoroacetic acid salt

To a solution of crudeN²-butyl-9-(tetrahydro-2H-pyran-2-yl)-9H-purine-2,6-diamine (˜10.2 g) indry chloroform (100 ml) at room temperature was added N-bromosuccinimide(6.3 g) in portions over 5 minutes. The dark solution was allowed tostir at room temperature for 30 minutes. The reaction mixture was washedwith water (20 ml). The organic phase was passed through a hydrophobicfrit and concentrated in vacuo. This afforded a beige solid which wasdissolved in dry methanol (100 ml) and at room temperature undernitrogen was added sodium methoxide solution (25 wt. % in methanol, 24ml) in one go. The reaction was heated at 65° C., with a condenserattached, overnight. The reaction was cooled and concentrated in vacuo.The resultant orange residue was taken up in ethyl acetate (150 ml) andpoured into saturated aqueous ammonium chloride (50 ml). The organiclayer was separated and washed further with water (50 ml). The organiclayer was dried over MgSO₄, filtered and concentrated in vacuo. To thismaterial in dry methanol (70 ml) at room temperature was addedtrifluoroacetic acid (7 ml) in one go. The reaction was stirred for 30hours and concentrated in vacuo to yield a dark brown solid. This wastaken up in diethyl ether (20 ml) and triturated. The solid was filteredto afford the title compound as a beige solid (3.3 g, 35%, 4 steps).

MS calcd for (C₁₀H₁₆N₆O)⁺=236

MS found (electrospray): (M+H)⁺=237

¹H NMR ((CD₃)₂SO): δ 13.3-12.3 (1H, br.m), 8.6-7.3 (2H, m), 4.05 (3H,s), 3.28 (2H, m), 1.52 (2H, m), 1.33 (2H, m), 0.89 (3H, t) (remainingexchangeable protons not clear).

Intermediate 11:N²-Butyl-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine-2,6-diamine

To a solution of N²-butyl-8-methoxy-9H-purine-2,6-diaminetrifluoroacetic acid salt (500 mg) in dry N,N-dimethylformamide (8 ml)at room temperature and under nitrogen was added potassium carbonate(1.17 g) in one go. The reaction was stirred at 60° C. for 1.5 hours andthen cooled to room temperature. 4-(bromomethyl)tetrahydro-2H-pyran (0.3ml) was added in one go and the reaction heated at 50° C. overnight. Thereaction was diluted with ethyl acetate (20 ml) and washed with water(10 ml). The organic layer was separated and concentrated in vacuo. Theproduct was purified by C₁₈ reverse phase chromatography using water(containing 0.1% formic acid)-acetonitrile (containing 0.05% formicacid) as eluant (10-45%) to afford the title compound as a yellowviscous oil (315 mg, 90% clean).

MS calcd for (C₁₆H₂₆N₆O₂)⁺=334

MS found (electrospray): (M+H)⁺=335

¹H NMR ((CD₃)₂SO): δ 6.29 (2H, s), 6.17 (1H, t), 4.00 (3H, s), 3.81 (2H,m), 3.66 (2H, d), 3.20 (4H, 2×m), 2.01 (1H, m), 1.47 (2H, m), 1.40 (2H,m), 1.31 (2H, m), 1.22 (2H, m), 0.89 (3H, t).

Intermediate 11, alternative procedure:N²-Butyl-8-(methoxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine-2,6-diamine

A mixture of N²-butyl-8-(methoxy)-3H-purine-2,6-diamine trifluoroacetate(12.89 g) and anhydrous potassium carbonate (20.58 g) in anhydrous DMF(175 mL) was heated to 60° C. (external) for 1.5 hours under nitrogen.The reaction mixture was cooled to room temperature before addingtetrahydro-2H-pyran-4-ylmethyl methanesulfonate (7.571 g) and then thereaction was heated to 90° C. for 2.5 hours. The reaction mixture wasexamined by LCMS and showed incomplete reaction and so the reactiontemperature was reduced to 50° C. (external) and the reaction mixturewas heated overnight under nitrogen.

The reaction mixture was then partitioned between water (300 mL) andethyl acetate (300 mL). The organic was separated and the aqueous layerwas re-extracted with further ethyl acetate (300 mL). The organicextracts were combined and washed with brine (500 mL). The organic wasdried by passing through a hydrophobic frit (after separating the brinelayer). The organic was evaporated under reduced pressure to give acrude brown mobile oil (16.01 g) that solidified to a wet solid (over 2days). This material in ˜3 g batches was purified using reverse phasechromatography {ISCO [column (C18) 330 g] (20-60% acetonitrile:water)}.The appropriate pure fractions from all purifications were combined andevaporated under reduced pressure to give clean title compound as alight-tan powdery solid (5.1530 g).

MS calcd for (C₁₆H₂₆N₆O₂)⁺=334

MS found (electrospray): (M+H)⁺=335

1H NMR (CDCl₃): 6.95 (2H, broad s), 6.52 (1H, broad s), 4.10 (3H, s),4.01-3.92 (2H, m), 3.80-3.73 (2H, m), 3.44-3.29 (4H, overlapping m),2.14-2.00 (1H, m), 1.65-1.34 (8H, overlapping m), 0.98-0.91 (3H, m).

Note: contains residual formic acid.

Intermediate 12:N²-Butyl-8-methoxy-9-(tetrahydro-2H-pyran-2-ylmethyl)-9H-purine-2,6-diamine

To a solution of N²-butyl-8-methoxy-9H-purine-2,6-diaminetrifluoroacetic acid salt (400 mg) in dry N,N-dimethylformamide (6 ml)at room temperature and under nitrogen was added potassium carbonate(630 mg) in one go. The reaction was stirred at 60° C. for 1.5 hours andthen cooled to 50° C. 2-(Bromomethyl)tetrahydro-2H-pyran (175 μl) wasadded in one go and the reaction heated to 50° C. overnight and then at90° C. for 2 hours. The reaction was diluted with ethyl acetate (20 ml)and washed with water (10 ml). The organic layer was separated andconcentrated in vacuo. The product was semi-purified by MDAP to afford amixture of the title compound and an isomer. This mixture was taken onwithout further purification.

MS calcd for (C₁₆H₂₆N₆O₂)⁺=334

MS found (electrospray): (M+H)⁺=335.

Intermediate 13: 3-(Bromomethyl)tetrahydro-2H-pyran

To tetrahydro-2H-pyran-3-ylmethanol (1 g) in dry dichloromethane (28 ml)at 0° C. and under nitrogen, was added triethylamine (2.7 ml) in one go,followed by methanesulphonyl chloride (0.87 ml) dropwise over 1 minute.The reaction was allowed to warm to room temperature and left at thistemperature overnight. The reaction mixture was diluted withdichloromethane (20 ml) and washed with saturated aqueous sodiumbicarbonate (20 ml). The organic layer was passed through a hydrophobicfrit to dry and concentrated in vacuo to yield a yellow oil. To this oilin dry acetone (40 ml) and at room temperature was added lithium bromide(3 g) in one go. The reaction was heated to reflux for 1 hour. Thereaction was allowed to cool to room temperature and taken up indichloromethane (60 ml) and washed with water (20 ml). The organic layerwas passed through a hydrophobic frit to dry and concentrated in vacuo.The product was purified by silica chromatography (40 g) (ISCO) using agradient elution of 0-50% cyclohexane:ethyl acetate to afford the titlecompound as a yellow oil (340 mg).

¹H NMR (CDCl₃): δ 3.99 (2H, m), 3.84 (1H, m), 3.41 (1H, m), 3.35-3.21(2H, m), 2.05-1.90 (2H, m), 1.71-1.59 (2H, m), 1.38 (1H, m).

Intermediate 14:N²-Butyl-8-methoxy-9-(tetrahydro-2H-pyran-3-ylmethyl)-9H-purine-2,6-diamine

To a solution of N²-butyl-8-methoxy-9H-purine-2,6-diaminetrifluoroacetic acid salt (100 mg) in dry N,N-dimethylformamide (1 ml)at room temperature and under nitrogen was added potassium carbonate(158 mg) in one go. The reaction was stirred at 60° C. for 1.5 hours andthen cooled to 50° C. A solution of 3-(bromomethyl)tetrahydro-2H-pyran(56 mg) in dry N,N-dimethylformamide (0.3 ml) was added in one go andthe reaction heated at 50° C. for 16 hours. The reaction was dilutedwith ethyl acetate (15 ml) and washed with water (5 ml). The organiclayer was separated, dried over magnesium sulphate, filtered, andconcentrated in vacuo. The product was purified by C₁₈ reverse phasechromatography using water (containing 0.1% formic acid)-acetonitrile(containing 0.05% formic acid) as eluant (20-60%) to afford the titlecompound as a yellow oil (45 mg).

MS calcd for (C₁₆H₂₆N₆O₂)⁺=334

MS found (electrospray): (M+H)⁺=335.

Intermediate 15: 3-(Bromomethyl)tetrahydrofuran

To tetrahydrofuran-3-ylmethanol (1 g) in dry dichloromethane (30 ml) at0° C. and under nitrogen, was added triethylamine (2.7 ml) in one go,followed by methanesulphonyl chloride (1 ml) dropwise over 3 minutes.The reaction was stirred at 0° C. until the ice in the bath melted andthen left at room temperature overnight. The reaction mixture was washedwith saturated aqueous sodium bicarbonate (10 ml). The organic layer waspassed through a hydrophobic frit to dry and concentrated in vacuo toyield a yellow oil (1.7 g). To this oil in dry acetone (50 ml) and atroom temperature was added lithium bromide (3.3 g) in one go. Thereaction was heated to reflux for 20 hours. The reaction was allowed tocool to room temperature and concentrated in vacuo. The residue wastaken up in dichloromethane (50 ml) and washed with water (25 ml). Theorganic layer was passed through a hydrophobic frit to dry andconcentrated in vacuo. The product was purified by silica chromatography(40 g) (ISCO) using a gradient elution of 0-50% cyclohexane:ethylacetate to afford the title compound as a colourless oil (890 mg).

¹H NMR ((CD₃)₂SO): δ 3.81-3.73 (2H, m), 3.66 (1H, m), 3.54 (2H, m), 3.42(1H, m), 2.61 (1H, m), 2.02 (1H, m), 1.60 (1H, m).

Intermediate 16:2-Butoxy-8-methoxy-9-(tetrahydrofuran-3-ylmethyl)-9H-purin-6-amine

2-Butoxy-8-methoxy-9H-purin-6-amine trifluoroacetate salt (0.20 g) wasdissolved in anhydrous N,N-dimethylformamide (5 mL) was treated withanhydrous potassium carbonate (0.315 g), heated to 60° C. for 1 hour andthen cooled to room temperature. To the above was added3-(bromomethyl)tetrahydrofuran (0.103 g) and the reaction mixture heatedat 50° C., overnight. The reaction mixture was quenched with water (25mL) and extracted into ethyl acetate (3 times, 100 mL combined totalvolume). The combined organic phase was separated and passed through ahydrophobic frit to dry. The organic phase was stripped to give a gumwhich was purified by C₁₈ reverse phase chromatography using water(containing 0.1% formic acid)-acetonitrile (containing 0.05% formicacid) as eluant (20-60%) to afford the title compound as a white solid(97 mg).

MS calcd for (C₁₅H₂₃N₅O₃)⁺=321

MS found (electrospray): (M+H)⁺=322

1H NMR (CDCl₃): 5.39 (2H, s), 4.24 (2H, t), 4.08 (3H, s), 3.96-3.85 (3H,overlapping m), 3.71 (2H, m), 3.60 (1H, m), 2.81 (1H, m), 1.93 (1H, m),1.76-1.63 (3H, overlapping m), 1.46 (2H, m), 0.93 (3H, t).

Intermediate 16, alternative procedure:2-(Butyloxy)-8-(methyloxy)-9-(tetrahydro-3-furanylmethyl)-9H-purin-6-amine

A solution of 2-butoxy-8-methoxy-9H-purin-6-amine trifluoroacetate salt(4.5 g), tetrahydro-3-furanylmethyl methanesulfonate (2.77 g) andpotassium carbonate (5.31 g) in dimethyl sulfoxide (45 ml) was stirredand heated at 60° C. for 1.5 hours, followed by heating at 90° C. for2.5 hours. The reaction was allowed to cool and the mixture diluted withwater and brine, and shaken with ethyl acetate. The insoluble solidpresent was filtered (209 mg of product) and the organic layerseparated. The aqueous layer was further extracted four times with ethylacetate. The combined organic layers were washed with water and thenbrine. The organic layer was dried by passing through a hydrophobic fritand concentrated in vacuo to yield a light brown solid (4.18 g). Thiswas recrystallised from acetonitrile (25 ml) to afford the product (2.28g). This was further purified by dissolving in dichloromethane andwashing with 1M hydrochloric acid, brine and saturated sodiumhydrogencarbonate. The organic layer was dried through a hydrophobicfrit and concentrated in vacuo to yield the product as a cream colouredsolid (2.03 g).

MS calcd for (C₁₅H₂₃N₅O₃)⁺=321

MS found (electrospray): (M+H)⁺=322

¹H NMR (CDCl₃): δ 5.32 (2H, broad s), 4.27 (2H, t), 4.12 (3H, s),4.00-3.88 (3H, m), 3.76 (2H, m), 3.63 (1H, m), 2.85 (1H, m), 1.97 (1H,m), 1.81-1.66 (3H, m), 1.49 (2H, m), 0.96 (3H, t).

Intermediate 17:2-Butoxy-8-methoxy-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-9H-purin-6-amine

2-Butoxy-8-methoxy-9H-purin-6-amine trifluoroacetate salt (0.2 g) inanhydrous N,N-dimethylformamide (5 mL) was treated with anhydrouspotassium carbonate (0.315 g) and then heated to 60° C. for 1 hour. Oncooling to room temperature, to the above was added4-(2-bromoethyl)tetrahydro-2H-pyran (0.110 g) and the reaction waswarmed to 50° C., overnight. The reaction mixture was quenched withwater (5 mL) and extracted into ethyl acetate (3 times, 100 mL combinedtotal volume). The separated organic layers were combined and passedthrough a hydrophobic frit to dry. The organic phase was stripped togive a gum which was purified by C₁₈ reverse phase chromatography usingwater (containing 0.1% formic acid)-acetonitrile (containing 0.05%formic acid) as eluant (20-60%) to afford the title compound as a whitesolid (111 mg).

MS calcd for (C₁₇H₂₇N₅O₃)⁺=349

MS found (electrospray): (M+H)⁺=350

1H NMR (CDCl₃): 5.20 (2H, s), 4.24 (2H, t), 4.10 (3H, s), 3.94 (4H,overlapping m), 3.31 (2H, m), 1.78-1.65 (6H, overlapping m), 1.52-1.39(3H, overlapping m), 1.30 (2H, m), 0.95 (3H, t).

Intermediate 18:2-Butoxy-8-methoxy-9-(tetrahydro-2H-pyran-3-ylmethyl)-9H-purin-6-amine

2-Butoxy-8-methoxy-9H-purin-6-amine trifluoroacetate salt (0.2 g) in dryN,N-dimethylformamide (5 mL) was heated at 60° C. with anhydrouspotassium carbonate (0.315 g) for 1 hour and allowed to cool to roomtemperature before adding 3-(bromomethyl)tetrahydro-2H-pyran (0.112 g).The reaction mixture was heated at 50° C., overnight. The reactionmixture was quenched with water (20 mL) and extracted into ethyl acetate(3 times, 75 mL combined volume). The organic phase was separated,combined and passed through a hydrophobic frit to dry. The organic phasewas evaporated under reduced pressure to give a yellow oil which waspurified by C₁₈ reverse phase chromatography using water (containing0.1% formic acid)-acetonitrile (containing 0.05% formic acid) as eluant(20-60%) to afford the title compound as a white solid (105.4 mg).

MS calcd for (C₁₆H₂₅N₅O₃)⁺=335

MS found (electrospray): (M+H)⁺=336

1H NMR (CDCl₃): 5.14 (2H, s), 4.26 (2H, t), 4.10 (3H, s), 3.88-3.72 (4H,overlapping m), 3.42 (1H, m), 3.27 (1H, dd), 2.18 (1H, m), 1.80-1.63(4H, overlapping m), 1.61-1.42 (3H, overlapping m), 1.33-1.18 (1H, m),0.95 (3H, t).

Intermediate 19: 2-(Tetrahydrofuran-2-yl)ethanol

A stirring solution of ethyl tetrahydrofuran-2-ylacetate (2.5 g) in dryTHF (25 ml) was cooled (ice bath) and 1M lithium aluminium hydride intetrahydrofuran added dropwise under nitrogen below 15° C. The reactionwas allowed to warm to ambient temperature and after 3 h re-cooled (icebath) and 5N sodium hydroxide (5.5 ml) carefully added below 10° C.Diethyl ether (50 ml) was then added and after 10 min the resultingsolid filtered and washed well with ether. The combined filtrate wasevaporated to give the title compound as a clear oil, yield 1.9 g.

¹H NMR (CDCl₃): δ 4.03 (1H, m), 3.91 (1H, m), 3.79 (2H, m), 3.74 (1H,m), 2.82 (1H, s), 2.03 (1H, m), 1.98-1.84 (2H, m), 1.84-1.70 (2H, m),1.63-1.50 (1H, m).

Intermediate 20: 2-(Tetrahydrofuran-2-yl)ethyl methanesulfonate

To an ice cooled stirring solution of 2-(tetrahydrofuran-2-yl)ethanol(1.9 g) and triethylamine (4.4 ml) in dry dichloromethane (30 ml) wasadded dropwise over 5 min methanesulphonyl chloride (1.59 ml). Themixture was allowed to warm slowly to ambient temperature over 16 h thenwashed with saturated sodium hydrogen carbonate. The aqueous layer wasfurther extracted with dichloromethane and the combined extracts washedwith brine, dried by passing through a phase separation cartridge andstripped to give the title compound as a light brown oil, yield 3.1 g.

¹H NMR (CDCl₃): δ 4.36 (2H, t), 3.96 (1H, m), 3.86 (1H, m), 3.74 (1H,m), 3.02 (3H, s), 2.01-1.84 (4H, m), 1.58-1.40 (2H, m).

Intermediate 21: 2-(2-Bromoethyl)tetrahydrofuran

2-(Tetrahydrofuran-2-yl)ethyl methanesulfonate (3.1 g) and anhydrouslithium bromide (6.57 g) in acetone (50 ml) were refluxed with stirringfor 3 h. After allowing to cool the solvent was stripped and the residuetreated with water and extracted three times with dichloromethane. Thecombined extracts were washed with saturated sodium hydrogen carbonate,dried by passing through a phase separation cartridge and stripped togive the title compound as an orange oil, yield 1.99 g.

¹H NMR (CDCl₃): δ 3.98 (1H, m), 3.85 (1H, m), 3.74 (1H, m), 3.50 (2H,m), 2.12-1.96 (3H, m), 1.96-1.85 (2H, m), 1.54-1.43 (1H, m).

Intermediate 22:2-Butoxy-8-methoxy-9-[2-(tetrahydrofuran-2-yl)ethyl]-9H-purin-6-amine

A stirring mixture of 2-butoxy-8-methoxy-1H-purin-6-aminetrifluoroacetate salt (200 mg) and potassium carbonate (236 mg) in dryN,N-dimethylformamide (2 ml) was heated with stirring at 60° C. for 1 h.2-(2-Bromoethyl)tetrahydrofuran (122 mg) was added and the stirringmixture heated at 50° C. for 4 h. After allowing to cool, water wasadded and the mixture extracted three times with ethyl acetate. Thecombined extracts were washed with water then brine, dried by passingthrough a phase separation cartridge and stripped to give a brown oil.This was purified by C₁₈ reverse phase chromatography using water(containing 0.1% formic acid)-acetonitrile (containing 0.05% formicacid) as eluent (20-60%) and the appropriate fractions combined andevaporated to remove acetonitrile. The remaining aqueous mixture wasmade basic with saturated sodium hydrogen carbonate, extracted threetimes with dichloromethane and the combined extracts dried by passingthrough a phase separation cartridge then evaporated to afford the titlecompound as a clear oil, yield 122 mg).

MS calcd for (C₁₆H₂₅N₅O₃)⁺=335

MS found (electrospray): (M+H)⁺=336

¹H NMR (CDCl₃): δ 5.10 (2H, s), 4.28 (2H, m), 4.12 (3H, s), 4.04 (2H,m), 3.85 (2H, m), 3.71 (1H, m), 1.98 (3H, m), 1.88 (2H, m), 1.77 (2H,m), 1.51 (3H, m), 0.97 (3H, t).

Intermediate 23:N²-Butyl-8-methoxy-9-[2-(tetrahydrofuran-2-yl)ethyl]-9H-purine-2,6-diamine

A stirring mixture of N²-butyl-8-methoxy-9H-purine-2,6-diaminetrifluoroacetic acid salt (200 mg) and potassium carbonate (236 mg) indry N,N-dimethylformamide (2 ml) was heated with stirring at 60° C. for1 h. 2-(2-Bromoethyl)tetrahydrofuran (122 mg) was added and the stirringmixture heated at 50° C. for 4 h. After allowing to cool, water wasadded and the mixture extracted three times with ethyl acetate. Thecombined extracts were washed with water then brine, dried by passingthrough a phase separation cartridge and stripped to give a brown oil.This was purified by C₁₈ reverse phase chromatography using water(containing 0.1% formic acid)-acetonitrile (containing 0.05% formicacid) as eluent (20-60%) and the appropriate fractions combined andevaporated to remove acetonitrile. The remaining aqueous mixture wasmade basic with saturated sodium hydrogen carbonate, extracted threetimes with dichloromethane and the combined extracts dried by passingthrough a phase separation cartridge then evaporated to afford the titlecompound, yield 107 mg.

MS calcd for (C₁₆H₂₆N₆O₂)⁺=334

MS found (electrospray): (M+H)⁺=335

¹H NMR (CDCl₃): δ 4.90 (2H, s), 4.58 (1H, br. t), 4.09 (3H, s), 3.98(2H, m), 3.86 (2H, m), 3.72 (1H, m), 3.38 (2H, m), 1.99 (3H, m), 1.88(2H, m), 1.57 (2H, m), 1.52-1.36 (3H, m), 0.95 (3H, t).

Intermediate 24: 5,6-Dihydro-2H-pyran-3-carbaldehyde

Conc. hydrochloric acid (5.5 ml) was added to water (28 ml) followed byacrolein (33.8 ml) and toluene (15 ml). The stirred mixture was heatedunder reflux at 75° C. for 1 h when reflux gradually abated. Afterallowing to cool, potassium carbonate was added until basic and themixture extracted twice with ether. The combined extracts were washedwith brine, dried (Na₂SO₄) and evaporated to a brown oil. Distillationat 6 mbar pressure gave the product as a pale yellow mobile liquid, by76-9° C., yield 4 g 14%).

¹H NMR (CDCl₃): δ 9.42 (1H, s), 6.94 (1H, m), 4.35 (2H, m), 3.82 (2H,m), 2.46 (2H, m).

Intermediate 25: Tetrahydro-2H-pyran-3-carbaldehyde

5,6-Dihydro-2H-pyran-3-carbaldehyde (2.98 gm) in ethanol (70 ml) wastreated with 10% wetted palladium on carbon catalyst under nitrogen,then hydrogenated at ambient temperature and pressure for 30 min. Thecatalyst was filtered off through Celite and the filtrate evaporated,then re-evaporated from toluene to give the product as an oil, yield2.58 g.

¹H NMR (CDCl₃): δ 9.72 (1H, s), 3.98 (1H, m), 3.82 (1H, m), 3.73 (1H,m), 3.58 (1H, m), 2.49 (1H, m), 1.95 (1H, m), 1.87 (1H, m), 1.70 (1H,m), 1.61 (1H, m).

Intermediate 26: 3-[(E,Z)-2-(Methoxy)ethenyl]tetrahydro-2H-pyran

A suspension of methoxymethyltriphenylphosphonium chloride (15.5 gm) indry THF (40 ml) was cooled to −40° C. and a solution of potassiumtert-butoxide (5.08 gm) in dry THF (40 ml) added dropwise with stirringunder nitrogen. After 45 min the mixture was further cooled to −65° C.and a solution of tetrahydro-2H-pyran-3-carbaldehyde (2.58 gm) in dryTHF (15 ml) added dropwise. The cooling bath was removed and afterallowing to warm to ambient temperature the reaction was stirred for afurther 30 min. The mixture was then quenched onto ice, extracted threetimes with ether and the combined extracts washed with brine, dried(Na₂SO₄) and evaporated then re-evaporated with toluene. The crudeproduct was purified by flash chromatography (silica, 0-20% ethylacetate-cyclohexane) to give the title compound as a colourless oil,yield 2.22 g (69%).

¹H NMR (CDCl₃): δ 6.36+5.89 (1H, m), 4.53+4.12 (1H, m), 3.88 (1H, m),3.78 (1H, m), 3.58+3.51 (3H, s), 3.34 (1H, m), 3.10 (1H, m), 2.73+2.20(1H, m), 1.84 (1H, m), 1.63 (2H, m), 1.30 (1H, m).

Intermediate 27: Tetrahydro-2H-pyran-3-ylacetaldehyde

To a stirring solution of 3-[2-(methoxy)ethenyl]tetrahydro-2H-pyran(2.22 gm) in THF (15 ml) was added 2N hydrochloric acid (15 ml). After 1h the mixture was diluted with water and extracted three times withether. The combined extracts were washed with brine, dried (Na₂SO₄) andevaporated to give the title product as a pale yellow oil, yield 1.79 g.

¹H NMR (CDCl₃): δ 9.77 (1H, s), 3.85 (2H, m), 3.43 (1H, m), 3.17 (1H,m), 2.34 (2H, m), 2.23 (1H, m), 1.90 (1H, m), 1.64 (2H, m), 1.27 (1H,m).

Intermediate 28: 2-(Tetrahydro-2H-pyran-3-yl)ethanol

A suspension of sodium borohydride (554 mg) in ethanol (20 ml) wascooled (ice bath) and a solution of tetrahydro-2H-pyran-3-ylacetaldehyde(1.88 gm) in ethanol (8 ml) added dropwise with stirring over 10 min.After 15 min the ice bath was removed and after a further 3 h themixture was heated at 50° C. for 1 h. After cooling the solvent wasevaporated and the residue treated with water and extracted three timeswith dichloromethane. The combined extracts were washed with dilutebrine, dried by passing through a hydrophobic frit and evaporated togive the title product as an oil. A further batch of product wasobtained by acidifying the aqueous solution with 2N hydrochloric acid,saturating with sodium chloride and extracting three times withdichloromethane. These extracts were treated as above and the batchescombined to give a total yield of 1.54 g (81%).

¹H NMR (CDCl₃): δ 3.88 (2H, m), 3.70 (2H, m), 3.38 (1H, m), 3.11 (1H,t), 1.89 (1H, m), 1.76 (1H, m), 1.61 (1H, m), 1.45 (2H, m), 1.22 (2H,m). OH not visible.

Intermediate 29: 2-(Tetrahydro-2H-pyran-3-yl)ethyl methanesulfonate

A solution of 2-(tetrahydro-2H-pyran-3-yl)ethanol (1.54 gm) andtriethylamine (3.3 ml) in dichloromethane (25 ml) was cooled (ice bath)and methanesulphonyl chloride (1.19 ml) added dropwise with stirringover 5 min. The reaction slowly warmed to ambient temperature as the icebath melted. After 16 h the mixture was washed with saturated aq. sodiumhydrogen carbonate, the aqueous layer extracted twice withdichloromethane and the combined extracts washed with dilute brine,dried by passing through a hydrophobic frit and evaporated to give thetitle compound as a brown oil, yield 2.38 g.

¹H NMR (CDCl₃): δ 4.27 (2H, t), 3.86 (2H, m), 3.41 (1H, m), 3.14 (1H,m), 3.02 (3H, s), 1.91 (1H, m), 1.8 (1H, m), 1.71 (1H, m), 1.63 (3H, m),1.23 (1H, m).

Intermediate 30:2-Butoxy-8-methoxy-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-9H-purin-6-amine

A stirring mixture of 2-butoxy-8-methoxy-9H-purin-6-aminetrifluoroacetate salt (200 mg) and potassium carbonate (236 mg) in dryN,N-dimethylformamide (2 ml) was heated with stirring at 60° C. for 1 h.2-(Tetrahydro-2H-pyran-3-yl)ethyl methanesulfonate (142 mg) was addedand the stirring mixture heated at 60° C. for 3 h. Water was added andthe mixture extracted three times with ethyl acetate. The combinedextracts were washed with water then brine, dried by passing through aphase separation cartridge and stripped to give a brown oil. This waspurified by C₁₈ reverse phase chromatography using water (0.1% formicacid)-acetonitrile (0.05% formic acid) as eluent (20-70%) and theappropriate fractions combined and evaporated to remove acetonitrile.The remaining aqueous mixture was made basic with saturated sodiumhydrogen carbonate, extracted three times with dichloromethane and thecombined extracts dried by passing through a phase separation cartridgethen evaporated to afford the title compound as a brown oil, yield 108mg.

MS calcd for (C₁₇H₂₇N₅O₃)⁺=349

MS found (electrospray): (M+H)⁺=350

¹H NMR (CDCl₃): δ 5.10 (2H, s), 4.28 (2H, t), 4.12 (3H, s), 3.96 (2H,t), 3.87 (2H, m), 3.38 (1H, m), 3.12 (1H, m), 1.96 (1H, m), 1.77 (2H,m), 1.71-1.44 (6H, m), 1.21 (2H, m), 0.97 (3H, t).

Intermediate 31:N²-Butyl-8-methoxy-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-9H-purine-2,6-diamine

A stirring mixture of N²-butyl-8-methoxy-9H-purine-2,6-diaminetrifluoroacetic acid salt (200 mg) and potassium carbonate (236 mg) indry N,N-dimethylformamide (2 ml) was heated with stirring at 60° C. for1 h. 2-(Tetrahydro-2H-pyran-3-yl)ethyl methanesulfonate (142 mg) wasadded and the stirring mixture heated at 60° C. for 3 h. Water was addedand the mixture extracted three times with ethyl acetate. The combinedextracts were washed with water then brine, dried by passing through aphase separation cartridge and stripped to give a brown oil. This waspurified by C₁₈ reverse phase chromatography using water (0.1% formicacid)-acetonitrile (0.05% formic acid) as eluent (20-60%) and theappropriate fractions combined and evaporated to remove acetonitrile.The remaining aqueous mixture was made basic with saturated sodiumhydrogen carbonate, extracted three times with dichloromethane and thecombined extracts dried by passing through a phase separation cartridgethen evaporated to afford the title compound as a brown solid, yield 138mg.

MS calcd for (C₁₇H₂₈N₆O₂)⁺=348

MS found (electrospray): (M+H)⁺=349

¹H NMR (CDCl₃): δ 4.89 (2H, br. s), 4.57 (1H, br. t), 4.08 (3H, s), 3.88(4H, m), 3.36 (3H, m), 3.12 (1H, m), 1.97 (1H, m), 1.68-1.52 (7H, m),1.40 (2H, m), 1.20 (1H, m), 0.94 (3H, t).

Intermediate 32: 2-(Tetrahydro-2H-pyran-4-yl)ethanol

To an ice-cold solution of lithium aluminium hydride (12.6 ml, 2.3Msolution in tetrahydrofuran) in dry tetrahydrofuran (20 ml) and undernitrogen, was added a solution of ethyl tetrahydro-2H-pyran-4-yl acetate(5 g) in dry tetrahydrofuran dropwise over 10 minutes. Following theaddition the reaction was heated to reflux, overnight. The reaction wascooled and diluted with diethyl ether (100 ml). A 5M aqueous solution ofsodium hydroxide (˜10 ml) was added cautiously to the reaction mixtureuntil the effervescence ceased. The formed white precipitate wasfiltered off. The resulting filtrate was dried over potassium carbonate,filtered and concentrated in vacuo. This yielded the title compound as acolourless oil (3.3 g).

MS calcd for (C₇H₁₄O₂)⁺=130

MS found (electrospray): (M+H)⁺=131

1H NMR (DMSO): 4.35 (1H, t), 3.80 (2H, m), 3.43 (2H, m), 3.25 (2H, m),1.60 (1H, m), 1.54 (2H, m), 1.35 (2H, m), 1.13 (2H, m).

Intermediate 33: 2-(Tetrahydro-2H-pyran-4-yl)ethyl methanesulfonate

To 2-(tetrahydro-2H-pyran-4-yl)ethanol (3.3 g) in dry dichloromethane(100 ml) at 0° C. and under nitrogen was added triethylamine (4.6 ml),followed by methanesulphonyl chloride (2.6 ml) dropwise over 5 minutes.The reaction was stirred until the ice in the bath melted and leftovernight at room temperature. The reaction was washed with saturatedaqueous sodium bicarbonate (40 ml). The organic layer was dried bypassing through a hydrophobic frit and concentrated in vacuo to yieldthe title compound as a yellow oil (5.4 g).

1H NMR (DMSO): 4.24 (2H, t), 3.82 (2H, m), 3.80 (3H, s), 3.27 (2H, m),2.50 (5H, m), 1.60 (2H, m).

Intermediate 34: 4-(2-Bromoethyl)tetrahydro-2H-pyran

To 2-(tetrahydro-2H-pyran-4-yl)ethyl methanesulfonate (5.4 g) in dryacetone at room temperature was added lithium bromide (9 g) in one go.The reaction was heated to reflux for 4 hours, under nitrogen. Thereaction was cooled to room temperature and concentrated in vacuo. Theresidue was taken up in dichloromethane (100 ml) and washed with water(50 ml). The organic layer was dried by passing through a hydrophobicfrit, and concentrated in vacuo. The product was purified by silicachromatography (40 g) (ISCO) using a gradient elution of 0-50%cyclohexane:ethyl acetate to afford the title compound as a colourlessoil (3.5 g).

1H NMR (DMSO): 3.82 (2H, m), 3.56 (2H, t), 3.26 (2H, m), 1.75 (2H, m),1.65 (1H, m), 1.57 (2H, m), 1.16 (2H, m).

Intermediate 35:2-[(2,2-Dimethylpentyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To a suspension of2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (500 mg) and2,2-dimethylpentanol (3.8 mL) at 50° C. was added sodium hydride (396mg, 60% dispersion) in portions. To the resultant viscous foam was addeda further portion of 2,2-dimethylpentanol (1.5 mL). The reaction wasstirred at 50° C. for 72 h. The reaction mixture was cooled thencarefully quenched with water (10 mL) and extracted with EtOAc (3×25mL). The organics were combined, washed with brine (30 mL), dried overMgSO₄, filtered and concentrated in vacuo to give a yellow oil. This wasazeotroped with toluene (×3) and the resulting viscous yellow oil waspurified by C₁₈ reverse phase chromatography (ISCO) using water (0.1%formic acid)-acetonitrile (0.05% formic acid) as eluent (30-80%) toafford the title compound as a brown solid (372 mg).

MS calcd for (C₁₇H₂₇N₅O₂)⁺=333

MS found (electrospray): (M+H)⁺=334

Intermediate 36:8-Bromo-2-[(2,2-dimethylpentyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To2-[(2,2-dimethylpentyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(372 mg) in dry chloroform (4.05 mL) at 0° C. was added NBS (209 mg) ina single portion. The reaction was warmed to room temperature and wasstirred for 5 h. The mixture was taken up into DCM (20 mL) and washedwith water (30 mL). The organics were separated and dried using ahydrophobic frit then concentrated in vacuo to afford the title compoundas a green/brown viscous foam (475 mg).

MS calcd for (C₁₇H₂₆BrN₅O₂)⁺=411/413

MS found (electrospray): (M+H)⁺=412/414

¹H NMR ((CD₃)₂SO): δ 7.48 (2H, br, s), 5.52 (1H, dd), 4.08-3.89 (3H, m),3.70 (1H, m), 2.97-2.83 (1H, m), 2.04-1.94 (1H, m), 1.89-1.51 (4H, m),1.35-1.21 (4H, m), 0.99-0.91 (6H, s), 0.90-0.84 (3H, m).

Intermediate 37:2-[(2,2-Dimethylpentyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To a solution of8-bromo-2-[(2,2-dimethylpentyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(475 mg) in dry MeOH (3.92 mL) was added sodium methoxide solution(0.649 mL, 30% wt. in MeOH). The reaction mixture was stirred at refluxfor 5 h. The reaction was cooled and concentrated in vacuo to give anorange residue. The residue was taken up in saturated ammonium chloridesolution (25 mL) and was extracted with EtOAc (25 mL). The organic layerwas separated and washed with water (15 mL). The organics wereseparated, dried over MgSO₄, filtered and concentrated in vacuo to givethe title compound as an orange solid (323 mg).

MS calcd for (C₁₈H₂₉N₅O₃)⁺=363

MS found (electrospray): (M+H)⁺=364

¹H NMR ((CD₃)₂SO): δ 6.85 (2H, s), 5.37 (1H, dd), 4.05 (3H, s),4.02-3.83 (3H, m), 3.63-3.54 (1H, m), 2.72-2.58 (1H, m), 1.97-1.91 (1H,m), 1.77-1.46 (4H, m), 1.31-1.23 (4H, m), 0.93 (6H, s), 0.89-0.83 (3H,m).

Intermediate 38: 2-[(2,2-Dimethylpentyl)oxy]-8-methoxy-9H-purin-6-aminetrifluoroacetic acid salt

To a solution of2-[(2,2-dimethylpentyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(323 mg) in dry MeOH (3.23 mL) was added TFA (0.323 mL) and the reactionwas stirred at room temperature for 48 h. The reaction was concentratedin vacuo to give a yellow residue. The residue was triturated with Et₂Oand was filtered to give the title compound as an off-white solid (252mg).

MS calcd for (C₁₃H₂₁N₅O₂)⁺=279

MS found (electrospray): (M+H)⁺=280

Intermediate 39:2-[(2,2-Dimethylpentyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

To a solution of 2-[(2,2-dimethylpentyl)oxy]-8-methoxy-9H-purin-6-aminetrifluoroacetic acid salt (252 mg) in dry DMF (3.97 mL) was addedpotassium carbonate (356 mg). The mixture was stirred at 60° C. for 90mins. The reaction was cooled and 4-(bromomethyl)tetrahydro-2H-pyran(127 mg) was added. The mixture was stirred at 50° C. for 6 h. Thereaction was cooled and taken up in EtOAc (40 mL). The mixture waswashed with water (2×20 mL) and the organics were separated, dried overMgSO₄ and concentrated in vacuo to give a viscous oil. The crudematerial was purified by C₁₈ reverse phase chromatography (ISCO) usingwater (0.1% formic acid)-acetonitrile (0.05% formic acid) as eluent(30-80%) to afford the title compound as an off-white solid (116 mg).

MS calcd for (C₁₉H₃₁N₅O₃)⁺=377

MS found (electrospray): (M+H)⁺=378

Intermediate 40:N²-Pentyl-9-(tetrahydro-2H-pyran-2-yl)-9H-purine-2,6-diamine

To a solution of 2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(500 mg) in dry ethylene glycol (2.3 mL) was added 1-pentylamine (689mg). The solution was stirred at reflux (120° C.) overnight. Thereaction was cooled, taken up in EtOAc (30 mL) and washed with water(2×20 mL). The organics were separated, dried over MgSO₄, filtered andconcentrated in vacuo to give the title compound as a viscous brown oil(561 mg).

MS calcd for (C₁₅H₂₄N₆O)⁺=304

MS found (electrospray): (M+H)⁺=305

¹H NMR ((CD₃)₂SO): δ 7.85 (1H, s), 6.62 (2H, s), 6.22 (1H, t), 5.40 (1H,dd), 4.01-3.95 (1H, m), 3.63-3.55 (1H, m), 3.26-3.19 (2H, m), 2.25-2.13(1H, m), 1.95 (1H, m), 1.85 (1H, m), 1.66 (1H, m), 1.60-1.15 (8H, m),0.87 (3H, m). Evidence of additional protons between 0.8-1.6-grease orhydrocarbon fragments.

Intermediate 41:8-Bromo-N²-pentyl-9-(tetrahydro-2H-pyran-2-yl)-9H-purine-2,6-diamine

A solution ofN²-pentyl-9-(tetrahydro-2H-pyran-2-yl)-9H-purine-2,6-diamine (543 mg) indry chloroform (4.6 mL) was cooled to 0° C. and NBS (334 mg) was added.The mixture was stirred at room temperature for 10 mins. The reactionwas taken up in DCM (30 mL) and was washed with water (30 mL). Theorganics were separated, dried using a hydrophobic frit and concentratedin vacuo to give the title compound as a viscous brown residue (627 mg)which was used crude in the next step.

MS calcd for (C₁₅H₂₃BrN₆O)⁺=382/384

MS found (electrospray): (M+H)⁺=383/385

Intermediate 42:8-Methoxy-N²-pentyl-9-(tetrahydro-2H-pyran-2-yl)-9H-purine-2,6-diamine

To a solution of8-bromo-N²-pentyl-9-(tetrahydro-2H-pyran-2-yl)-9H-purine-2,6-diamine(607 mg) in dry MeOH (4.75 mL) was added sodium methoxide solution(0.906 mL, 30% wt. MeOH) and the mixture was stirred at 60° C. for 48 h.The reaction was concentrated in vacuo. The residue was taken up inEtOAc (25 mL) and washed with saturated ammonium chloride (25 mL). Theorganics were separated, dried over MgSO₄, filtered and concentrated invacuo to give the title compound as a red/brown viscous oil (520 mg)which was used crude in the next step.

MS calcd for (C₁₆H₂₆N₆O₂)⁺=334

MS found (electrospray): (M+H)⁺=335

Intermediate 43: 8-Methoxy-N²-pentyl-9H-purine-2,6-diaminetrifluoroacetic acid salt

To a solution of8-methoxy-N²-pentyl-9-(tetrahydro-2H-pyran-2-yl)-9H-purine-2,6-diamine(520 mg) in dry MeOH (5.2 mL) was added TFA (0.52 mL) and the mixturewas stirred at room temperature for 48 h. The reaction was concentratedin vacuo to give an orange residue which was triturated with Et₂O andfiltered to give the title compound as an off-white solid (223 mg).

MS calcd for (C₁₁H₁₈N₆O)⁺=250

MS found (electrospray): (M+H)⁺=251

¹H NMR ((CD₃)₂SO): δ 13.02-12.15 (1H, br.d), 8.33-7.18 (2H, br.m), 4.04(3H, s), 3.32-3.17 (2H, m), 1.59-1.47 (2H, m), 1.38-1.20 (4H, m), 0.88(3H, t), one exchangeable proton not seen.

Intermediate 44:8-Methoxy-N²-pentyl-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine-2,6-diamine

To a solution of 8-methoxy-N²-pentyl-9H-purine-2,6-diaminetrifluoroacetic acid salt (223 mg) in dry DMF (3.85 mL) was addedpotassium carbonate (339 mg) at 60° C. and the mixture was stirred for90 mins. The mixture was cooled to room temperature and4-(bromomethyl)tetrahydro-2H-pyran (121 mg) was added in one portion.The reaction was stirred at 50° C. overnight and was then cooled andtaken up in EtOAc (20 mL). The organics were washed with water (2×10mL), separated, dried over MgSO₄, filtered and concentrated in vacuo togive an off-white solid. The crude material was purified by C₁₈ reversephase chromatography (ISCO) using water (0.1% formic acid)-acetonitrile(0.05% formic acid) as eluent (20-60%) to afford the title compound asan off-white solid (140 mg).

MS calcd for (C₁₇H₂₈N₆O₂)⁺=348

MS found (electrospray): (M+H)⁺=349

Intermediate 45:2-[(3-Methylbutyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To 3-methyl-1-butanol (1.03 mL) in DME (5 mL) was added sodiumtert-butoxide (912 mg) in portions over 5 mins with stirring. Themixture was stirred at room temperature until homogeneous.2-Chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (600 mg) wasadded followed by DME (4.6 mL). The reaction was heated at 110° C.overnight. The reaction was allowed to cool, was taken up in water (20mL) and washed with EtOAc (2×20 mL). The organics were extracted withbrine, separated, dried over MgSO₄, filtered and concentrated in vacuoto give a viscous yellow oil. The crude material was purified by C₁₈reverse phase chromatography (ISCO) using water (0.1% formicacid)-acetonitrile (0.05% formic acid) as eluent (30-80%) to afford thetitle compound as a yellow residue (266 mg).

MS calcd for (C₁₅H₂₃N₅O₂)⁺=305

MS found (electrospray): (M+H)⁺=306

Intermediate 46:8-Bromo-2-[(3-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To a solution of2-[(3-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(266 mg) in dry chloroform (3.15 mL) at 0° C. was added NBS (163 mg).The reaction was warmed to room temperature and was stirred for 5 h. Thereaction was taken up into DCM (20 mL) and extracted with water (20 mL).The organics were separated, dried using a hydrophobic frit andconcentrated in vacuo to give the title compound as a green/brown solid(314 mg).

MS calcd for (C₁₅H₂₂BrN₅O₂)⁺=383/385

MS found (electrospray): (M+H)⁺=384/386

¹H NMR ((CD₃)₂SO): δ 7.38 (2H, br.s), 5.49 (1H, dd), 4.24 (2H, t), 4.03(1H, d), 3.68-3.57 (1H, m), 3.03-2.90 (1H, m), 2.03-1.50 (8H, m), 0.92(6H, d).

Intermediate 47:2-[(3-Methylbutyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To a solution of8-bromo-2-[(3-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(314 mg) was added sodium methoxide solution (0.460 mL, 30% wt. MeOH)and the mixture was stirred at reflux for 4 h. The reaction was allowedto cool and was concentrated in vacuo to give an orange residue. Theresidue was taken up in EtOAc (20 mL) and was extracted with saturatedammonium chloride solution (20 mL), followed by water (20 mL). Theorganics were separated, dried over MgSO₄, filtered and concentrated invacuo to give the title compound as a light orange solid (210 mg).

MS calcd for (C₁₆H₂₅N₅O₃)⁺=335

MS found (electrospray): (M+H)⁺=336

¹H NMR ((CD₃)₂SO): δ 6.81 (2H, br.s), 5.34 (1H, dd), 4.26-4.15 (2H, m),4.05 (3H, s), 3.96 (1H, d), 3.61-3.52 (1H, m), 2.77-2.66 (1H, m),1.98-1.90 (1H, m), 1.79-1.46 (7H, m), 0.92 (6H, d).

Intermediate 48: 2-[(3-Methylbutyl)oxy]-8-methoxy-9H-purin-6-aminetrifluoroacetic acid salt

To a solution of2-[(3-methylbutyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(210 mg) in dry MeOH (2.1 mL) was added TFA (0.21 ml) and the mixturewas stirred at room temperature for 24 h. The reaction was concentratedin vacuo to give a yellow residue which was triturated with Et₂O (15 mL)and filtered under reduced pressure to give the title compound as anoff-white solid (143 mg).

MS calcd for (C₁₁H₁₇N₅O₂)⁺=251

MS found (electrospray): (M+H)⁺=252

¹H NMR ((CD₃)₂SO): δ 7.90 (1H, br), 4.38-4.30 (2H, m), 4.05 (3H, s),1.79-1.68 (1H, m), 1.65-1.56 (2H, m), 0.93 (6H, d) two exchangeableprotons not seen.

Intermediate 49:2-[(3-Methylbutyl)oxy]-8-(methoxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

To a solution of 2-[(3-methylbutyl)oxy]-8-methoxy-9H-purin-6-aminetrifluoroacetic acid salt (143 mg) in dry DMF (2.42 mL) was addedpotassium carbonate (217 mg) and the mixture was stirred at 60° C. for90 mins. The reaction was cooled and 4-(bromomethyl)tetrahydro-2H-pyran(77 mg) was added. The reaction was stirred at 50° C. overnight and wascooled to room temperature. The mixture was taken up in EtOAc (30 mL)and extracted with water (2×15 mL). The organics were separated, driedover MgSO₄ and concentrated in vacuo to give a viscous yellow oil. Thecrude material was purified by C₁₈ reverse phase chromatography (ISCO)using water (0.1% formic acid)-acetonitrile (0.05% formic acid) aseluent (20-60%) to afford the title compound as a clear viscous oil (52mg).

MS calcd for (C₁₇H₂₇N₅O₃)⁺=349

MS found (electrospray): (M+H)⁺=350

Intermediate 50:2-[(2-Methylbutyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To 2-methyl-1-butanol (0.855 mL) in DME (4 mL) was added sodiumtert-butoxide (760 mg). The mixture was stirred at room temperatureuntil homogeneous.2-Chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (500 mg) wasadded followed by DME (4 mL). The reaction was heated at 110° C.overnight. The mixture was cooled and concentrated in vacuo to give ayellow residue. The residue was taken up in water (30 mL) and extractedwith EtOAc (2×30 mL). The organics were separated and washed with brine(30 mL). The organics were separated, dried over MgSO₄, filtered andconcentrated in vacuo to give the title compound as a yellow/brownresidue. This material was taken on to the next step without furtherpurification.

MS calcd for (C₁₅H₂₃N₅O₂)⁺=305

MS found (electrospray): (M+H)⁺=306

Intermediate 51:8-Bromo-2-[(2-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

A solution of2-[(2-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(245 mg) in dry chloroform (2.9 mL) was cooled to 0° C. and NBS (150 mg)was added to give a green/brown solution. The reaction mixture wasstirred at room temperature for 6 h. The mixture was taken up into DCM(20 mL) and was washed with water (20 mL). The organics were separated,dried by passing through a hydrophobic frit and concentrated in vacuo togive the title compound as green solid (292 mg).

MS calcd for (C₁₅H₂₂BrN₅O₂)⁺=383/385

MS found (electrospray): (M+H)⁺=384/386

¹H NMR ((CD₃)₂SO): δ 7.39 (2H, br), 5.50 (1H, dd), 4.15-4.07 (1H, m),4.06-3.95 (2H, m), 3.70-3.57 (1H, m), 3.02-2.88 (1H, m), 2.03-1.40 (7H,m), 1.27-1.13 (1H, m), 0.99-0.84 (6H, m).

Intermediate 52:2-[(2-Methylbutyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To a solution of8-bromo-2-[(2-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(284 mg) in dry MeOH (2.54 mL) was added sodium methoxide solution(0.416 mL, 30% wt. MeOH) and the mixture was stirred at reflux for 1 h.The reaction was allowed to cool and was concentrated in vacuo. Theresulting residue was dissolved in EtOAc (15 mL) and was poured intosaturated ammonium chloride solution (15 mL). The organics wereseparated, dried over MgSO₄, filtered and concentrated in vacuo to givethe title compound as an orange foam (199 mg).

MS calcd for (C₁₆H₂₅N₅O₃)⁺=335

MS found (electrospray): (M+H)⁺=336

¹H NMR ((CD₃)₂SO): δ 6.87 (2H, s), 5.35 (1H, dd), 4.13-3.91 (6H, m),3.66-3.50 (1H, m), 2.77-2.62 (1H, m), 1.98-1.42 (7H, m), 1.26-1.13 (1H,m), 0.98-0.85 (6H, m).

Intermediate 53: 2-[(2-Methylbutyl)oxy]-8-(methoxy)-9H-purin-6-aminetrifluoroacetic acid salt

To a solution of2-[(2-methylbutyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(199 mg) in dry MeOH (1.99 mL) was added TFA (0.199 mL). The mixture wasstirred at room temperature for 24 h. The reaction was concentrated invacuo to give a yellow residue. The residue was triturated with Et₂O andwas filtered to give the title compound as an off-white solid (111 mg).

MS calcd for (C₁₁H₁₇N₅O₂)⁺=251

MS found (electrospray): (M+H)⁺=252

¹H NMR ((CD₃)₂SO): δ 8.01-7.46 (2H, br), 4.20-4.00 (6H, m), 1.88-1.73(1H, m), 1.54-1.40 (1H, m), 1.28-1.12 (1H, m), 0.99-0.84 (6H, m).

Intermediate 54:2-[(2-Methylbutyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

To a solution of 2-[(2-methylbutyl)oxy]-8-methoxy-9H-purin-6-amine (109mg) in dry DMF (1.86 mL) was added potassium carbonate (165 mg) and themixture was stirred at 60° C. for 90 mins. The mixture was cooled toroom temperature and 4-(bromomethyl)tetrahydro-2H-pyran (59 mg) wasadded. The reaction was stirred at 50° C. overnight and was cooled toroom temperature. The mixture was taken up in EtOAc (15 mL) and washedwith water (2×10 mL). The organics were separated, dried over MgSO₄,filtered and concentrated in vacuo to give a yellow viscous oil. Thematerial was purified by C₁₈ reverse phase chromatography (ISCO) usingwater (0.1% formic acid)-acetonitrile (0.05% formic acid) as eluent(20-60%) to afford the title compound as a yellow oil (41 mg).

MS calcd for (C₁₇H₂₇N₅O₃)⁺=349

MS found (electrospray): (M+H)⁺=350

Intermediate 55:2-[(1-Methylbutyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To 2-pentanol (3.65 mL) was added sodium tert-butoxide (760 mg) inportions over 5 mins. The mixture was stirred at room temperature untilhomogeneous. 2-Chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (500mg) was added and the reaction was heated at 50° C. overnight, then fora further 72 h. The reaction mixture was cooled and quenched with water(10 mL) and was extracted with EtOAc (3×25 mL). The organics werecombined, washed with brine (30 mL), dried over MgSO₄, filtered andconcentrated in vacuo to give crude title compound as a viscous yellowoil.

In a separate flask, a suspension of2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (500 mg) and2-pentanol (3.8 mL) was heated to 50° C. Sodium hydride (396 mg, 60%dispersion) was added in portions and the reaction was stirred at 50° C.for 72 h. The reaction was cooled and quenched with water (10 mL) andwas extracted with EtOAc (3×25 mL). The combined organics were washedwith brine (30 mL), dried over MgSO₄, filtered and concentrated in vacuoto give crude title compound as a yellow oil.

The two crude reaction products were combined and purified by C₁₈reverse phase chromatography (ISCO) using water (0.1% formicacid)-acetonitrile (0.05% formic acid) as eluent (20-60%) to afford thetitle compound as a brown oil (382 mg).

MS calcd for (C₁₅H₂₃N₅O₂)⁺=305

MS found (electrospray): (M+H)⁺=306

Intermediate 56:8-Bromo-2-[(1-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To a solution of2-[(1-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(382 mg) in dry chloroform (4.52 mL) at 0° C. was added NBS (234 mg) ina single portion. The reaction was warmed to room temperature andstirred for 5 h. The reaction mixture was taken up in DCM (20 mL) andwas washed with water (30 mL). The organics were separated, dried bypassing through a hydrophobic frit and concentrated in vacuo to give agreen/brown foam (493 mg).

MS calcd for (C₁₅H₂₂BrN₅O₂)⁺=383/385

MS found (electrospray): (M+H)⁺=384/386

¹H NMR ((CD₃)₂SO): δ 7.44 (2H, br), 5.48 (1H, dd), 5.09-4.98 (1H, m),4.07-3.98 (1H, m), 3.68-3.57 (1H, m), 3.02-2.88 (1H, m), 2.03-1.91 (1H,m), 1.87-1.79 (1H, m), 1.74-1.45 (5H, m), 1.44-1.20 (5H, m), 0.95-0.85(3H, m).

Intermediate 57:2-[(1-Methylbutyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To a solution of8-bromo-2-[(1-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(493 mg) in dry MeOH (4.37 mL) was added sodium methoxide solution(0.722 mL, 30% wt. in MeOH) and the mixture was stirred at reflux for 6h. A further portion of sodium methoxide solution (0.120 mL, 30% wt. inMeOH) was added and the reaction was continued for 90 mins. The reactionwas cooled and concentrated in vacuo to give an orange residue. Theresidue was taken up in saturated ammonium chloride (25 mL) and washedwith EtOAc (25 mL). The organics were separated and washed with water(15 mL). The organics were separated, dried over MgSO₄, filtered andconcentrated in vacuo to give the title compound as an orange foam (313mg).

MS calcd for (C₁₆H₂₅N₅O₃)⁺=335

MS found (electrospray): (M+H)⁺=336

¹H NMR ((CD₃)₂SO): δ 6.78 (2H, s), 5.33 (1H, d), 5.07-4.96 (1H, m),4.09-3.92 (4H, m), 3.62-3.49 (1H, m), 2.80-2.64 (1H, m), 1.97-1.88 (1H,m), 1.77-1.43 (6H, m), 1.42-1.19 (5H, m), 0.95-0.84 (3H, m).

Intermediate 58: 2-[(1-Methylbutyl)oxy]-8-methoxy-9H-purin-6-aminetrifluoroacetic acid salt

To a solution of2-[(1-methylbutyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(313 mg) in dry MeOH (3.13 mL) was added TFA (0.313 mL) and the mixturewas stirred at room temperature for 48 h. The reaction mixture wasconcentrated in vacuo to give a yellow residue which was triturated withEt₂O and filtered to give the title compound as an off-white solid (218mg).

MS calcd for (C₁₁H₁₇N₅O₂)⁺=251

MS found (electrospray): (M+H)⁺=252

¹H NMR ((CD₃)₂SO): δ 8.12 (2H, br), 5.20-5.09 (1H, m), 4.05 (3H, s),1.74-1.52 (2H, m), 1.45-1.27 (5H, m), 0.94-0.85 (3H, m), oneexchangeable proton not seen.

Intermediate 59:2-[(1-Methylbutyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

To a solution of 2-[(1-methylbutyl)oxy]-8-methoxy-9H-purin-6-aminetrifluoroacetic acid salt (218 mg) in dry DMF (3.71 mL) was addedpotassium carbonate (330 mg). The mixture was stirred at 60° C. for 90mins. The reaction was cooled and 4-(bromomethyl)tetrahydro-2H-pyran(118 mg) was added. The reaction was stirred at 50° C. for 6 h and wascooled to room temperature. The mixture was taken up in EtOAc (40 mL)and washed with water (2×20 mL). The organics were separated, dried overMgSO₄ and concentrated in vacuo to give a viscous yellow oil. Thematerial was purified by C₁₈ reverse phase chromatography (ISCO) usingwater (0.1% formic acid)-acetonitrile (0.05% formic acid) as eluent(20-60%) to afford the title compound as a clear oil (92 mg).

MS calcd for (C₁₇H₂₇N₅O₃)⁺=349

MS found (electrospray): (M+H)⁺=350

Intermediate 60: 2-Chloro-1H-purin-6-amine

A mixture of 2,6-dichloro-1H-purine (5 g) and ammonia solution (79.2 mL,2M in (isopropanol) was stirred and heated at 120° C. in an autoclaveovernight. The reaction was cooled and concentrated in vacuo to give thetitle compound as an off-white solid in quantitative yield.

MS calcd for (C₅H₄ClN₅)⁺=169/171

MS found (electrospray): (M+H)⁺=170/172

¹H NMR ((CD₃)₂SO): δ 8.14 (1H, s), 7.66 (2H, s), one exchangeable protonnot seen.

Intermediate 61:2-Chloro-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

To a suspension of 2-chloro-1H-purin-6-amine (1.57 g) and potassiumcarbonate (2.57 g) in DMF (55 mL) was added4-(bromomethyl)tetrahydro-2H-pyran (2.0 g) in one portion. The mixturewas stirred at 90° C. overnight. The reaction mixture was taken up inchloroform/isopropanol (3:1, 100 mL) and was extracted with water (100mL). The organics were separated and the aqueous was extracted withchloroform/isopropanol (3:1, 2×50 mL). The organics were combined, driedby passing through a hydrophobic frit and concentrated in vacuo to givethe title compound as an off-white solid (1.30 g, 52%).

MS calcd for (C₁₁H₁₄ClN₅O)⁺=267/269

MS found (electrospray): (M+H)⁺=268/270

¹H NMR ((CD₃)₂SO): δ 8.13 (1H, s), 7.73 (2H, br.s), 4.00 (2H, d), 3.81(2H, dd), 3.28-3.17 (2H, m), 2.14-1.99 (1H, m), 1.43-1.33 (2H, m),1.33-1.17 (2H, m).

Intermediate 62:8-Bromo-2-chloro-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

To a solution of2-chloro-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine (1.30 g) indry chloroform (32 mL) at room temperature was added NBS (2.16 g). Thereaction was stirred at 60° C. for 6 h. the mixture was cooled, taken upin DCM (50 mL) and washed with water (50 mL). The organics were passedthrough a hydrophobic frit and concentrated in vacuo to give the titlecompound as a brown solid (1.36 g).

MS calcd for (C₁₁H₁₃BrClN₅O)⁺=345/347/349

MS found (electrospray): (M+H)⁺=346/348/350

¹H NMR ((CD₃)₂SO): δ 7.91 (2H, br), 4.04-3.94 (1H, m), 3.82 (2H, dd),3.31-3.15 (2H, m), 2.19-2.01 (1H, m), 1.48-1.15 (5H, m).

Intermediate 63:2-Chloro-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

To a solution of8-bromo-2-chloro-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(1.36 g) in dry MeOH (27.5 mL) was added 1M sodium hydroxide solution(27.5 mL) and the mixture was stirred at reflux for 30 mins. Thereaction was cooled to room temperature and concentrated in vacuo. Theresidue obtained was triturated with water (60 mL) and extracted withEtOAc (120 mL). The organic layer was washed with brine (60 mL), driedover MgSO₄, filtered and concentrated in vacuo to give a pink/whitesolid. The material was taken up in MeOH/DMSO (1:1) and a precipitatecrashed out of solution. The solid was filtered off and the filtrate waspurified by C₁₈ reverse phase chromatography (ISCO) using water (0.1%formic acid)-acetonitrile (0.05% formic acid) as eluent (10-45%). Thefiltered solid was combined with the material obtained from thepurification to give the title compound (192 mg).

MS calcd for (C₁₂H₁₆ClN₅O₂)⁺=297/299

MS found (electrospray): (M+H)⁺=298/300

¹H NMR ((CD₃)₂SO): δ 7.45-7.28 (2H, m), 4.10 (3H, s), 3.87-3.73 (3H, m),3.22 (3H, t), 2.07-1.93 (1H, m), 1.46-1.36 (2H, m), 1.33-1.14 (2H, m).

Intermediate 64:2-[(2-Cyclopropylethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To a mixture of 2-cyclopropylethanol (3.45 g) in DME (20 mL) was addedsodium tert-butoxide (3.86 g) gradually. The reaction was stirred undernitrogen for 30 mins, then2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (2.54 g) and DME(20 mL) were added. The reaction was heated to reflux (110° C.)overnight, then for another 8 h. The reaction was quenched into water(100 mL) and extracted with EtOAc (2×100 mL). The organics were combinedand washed with brine (100 mL) and dried using a hydrophobic frit. Theresultant oil was azeotroped with toluene (×2) to give a gum. This wastriturated with Et₂O (cooled CO₂/acetone bath) until the title compoundwas obtained as a yellow powder (1.579 g) which was placed under highvacuum for 24 h.

MS calcd for (C₁₅H₂₁N₅O₂)⁺=303

MS found (electrospray): (M+H)⁺=304

¹H NMR (CDCl₃): δ 7.85 (1H, s), 5.64 (1H, dd), 5.51 (2H, br), 4.39 (2H,dt), 4.19-4.11 (1H, m), 3.80-3.71 (1H, m), 2.13-1.94 (3H, m), 1.83-1.59(5H, m), 0.94-0.82 (1H, m), 0.53-0.43 (2H, m), 0.16-0.09 (2H, m).

Intermediate 65:8-Bromo-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

2-[(2-Cyclopropylethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(1.579 g) was dissolved in chloroform (15 mL) and was cooled in an icebath to 1° C. NBS (1.02 g) was added gradually, keeping the reactiontemperature below 2° C. The reaction was stirred for 30 mins (withcooling in an ice bath) before being allowed to warm to roomtemperature. The reaction was then stirred for 6 h. Chloroform (50 mL)was added and the mixture was partitioned with water (50 mL) and wasseparated using a hydrophobic frit. The organics were evaporated underreduced pressure to give the title compound as a brown foam (1.867 g).

MS calcd for (C₁₅H₂₀BrN₅O₂)⁺=381/383

MS found (electrospray): (M+H)⁺=382/384

¹H NMR (CDCl₃): δ 5.62 (1H, dd), 5.45 (2H, br), 4.44-4.34 (2H, m),4.22-4.14 (1H, m), 3.72 (1H, dt), 3.11-2.99 (1H, m), 2.16-2.07 (1H, m),1.90-1.58 (6H, m), 0.93-0.82 (1H, m), 0.53-0.46 (2H, m), 0.16-0.10 (2H,m).

Intermediate 66:2-[(2-Cyclopropylethyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

A solution of8-bromo-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(1.867 g) in dry MeOH (14 mL) was treated with sodium methoxide solution(3.1 mL, 25 wt. MeOH) and was heated to reflux for 5 h. The reaction wasconcentrated under reduced pressure before being partitioned betweenEtOAc (100 mL) and ammonium chloride (100 mL). The organics wereseparated and aqueous was re-extracted with EtOAc (100 mL). The combinedorganics were washed with brine (100 mL), separated and dried using ahydrophobic frit. The organics were evaporated under reduced pressure togive the title compound as a brown foam (845 mg).

MS calcd for (C₁₆H₂₃N₅O₃)⁺=333

MS found (electrospray): (M+H)⁺=334

¹H NMR (CDCl₃): δ 5.51 (1H, dd), 5.13 (2H, br), 4.36 (2H, t), 4.13 (3H,t), 3.70 (1H, dt), 2.84-2.72 (1H, m), 2.10-2.01 (1H, m), 1.82-1.53 (7H,m), 0.93-0.82 (1H, m), 0.52-0.45 (2H, m), 0.16-0.09 (2H, m).

Intermediate 67: 2-[(2-Cyclopropylethyl)oxy]-8-methoxy-9H-purin-6-aminetrifluoroacetic acid salt

2-[(2-Cyclopropylethyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(845 mg) was dissolved in MeOH (10 mL) and TFA (1 mL) was added. Thereaction was stirred over a weekend and was evaporated to dryness underreduced pressure to give a brown solid. EtOAc was added and the solidwas filtered off and washed with more EtOAc (15 mL EtOAc used in total).The solid was then washed with Et₂O (5 mL) and air-dried under suctionto give the title compound as an off-white solid (937 mg).

MS calcd for (C₁₁H₁₅N₅O₂)⁺=249

MS found (electrospray): (M+H)⁺=250

¹H NMR (CDCl₃): δ 7.91 (2H, br), 4.24 (2H, t), 3.93 (3H, s), 1.53-1.45(2H, m), 0.71-0.60 (1H, m), 0.34-0.27 (2H, m), 0.02-0.04 (2H, m), oneexchangeable proton not seen, trace of ammonium ion present.

Intermediate 68: Tetrahydro-3-furanylmethyl methanesulfonate

To tetrahydro-3-furanmethanol (25 g) in dry DCM (250 mL) at 0° C. undernitrogen was added triethylamine (68 mL) in a single portion.Methanesulphonyl chloride (24.7 mL) was added dropwise over 15 mins. Thereaction was warmed to room temperature and was left over a weekend. Themixture was taken up in DCM (50 mL) and washed with saturated sodiumbicarbonate solution (100 mL). The organics were dried using ahydrophobic frit and concentrated in vacuo to give the title compound asa brown oil in quantitative yield.

¹H NMR ((CD₃)₂SO): δ 4.19-4.08 (2H, m), 3.77-3.69 (2H, m), 3.66-3.59(1H, m), 3.46 (1H, dd), 3.19 (3H, s), 2.64-2.53 (1H, m), 2.03-1.92 (1H,m), 1.63-1.53 (1H, m).

Intermediate 69:2-[(2-Cyclopropylethyl)oxy]-8-methoxy-9-(tetrahydro-3-furanylmethyl)-9H-purin-6-amine

To a solution of 2-[(2-cyclopropylethyl)oxy]-8-methoxy-9H-purin-6-aminetrifluoroacetic acid salt (300 mg) in dry DMF (5 mL) was added anhydrouspotassium carbonate (457 mg) and the mixture was heated at 60° C. for1.5 h. The reaction was cooled to room temperature andtetrahydro-3-furanylmethyl methanesulfonate (164 mg) was added. Thereaction was heated at 90° C. for 3.5 h and was then quenched into water(50 mL) and extracted with EtOAc (3×50 mL). The organics were separated,dried by passing through a hydrophobic frit and evaporated under reducedpressure to give a glassy solid. The material was purified by C₁₈reverse phase chromatography (ISCO) using water (0.1% formicacid)-acetonitrile (0.05% formic acid) as eluent (20-60%) to give thetitle compound (103.8 mg).

MS calcd for (C₁₆H₂₃N₅O₃)⁺=333

MS found (electrospray): (M+H)⁺=334

¹H NMR (CDCl₃): δ 5.37 (2H, br), 4.22 (2H, t), 4.00 (3H, s), 3.89-3.77(3H, m), 3.69-3.61 (2H, m), 3.52 (1H, dd), 2.80-2.67 (1H, m), 1.91-1.81(1H, m), 1.65-1.53 (3H, m), 0.80-0.69 (1H, m), 0.39-0.32 (2H, m),0.02-0.04 (2H, m).

Intermediate 70: 2-[(E/Z)-2-methoxyethenyl]tetrahydro-2H-pyran

A solution of oxalyl chloride (5.33 mL) in DCM (30 mL) was cooled to−60° C. and a solution of DMSO (7.4 mL) in DCM (100 mL) was addeddropwise with stirring, keeping the temperature between −55° C. and −60°C. After 20 mins tetrahydro-2H-pyran-2-ylmethanol (6 g) was addeddropwise. After 30 mins, triethylamine (36 mL) was added dropwise andafter a further 30 mins the mixture was allowed to warm to roomtemperature. After 30 mins the mixture was treated with water, themixture was shaken and the layers separated. The aqueous layer wasextracted with DCM (×2) and the combined extracts were washed withdilute brine, dried using a hydrophobic frit and evaporated to a paleoil (3.8 g). The material was purified by normal phase chromatography(ISCO) using cyclohexane/EtOAc as eluent (0-40%) to give a clear oil(780 mg).

A suspension of (methoxymethyl)triphenylphosphonium chloride (4.69 g) indry THF was cooled to −40° C. and a solution of potassium tert-butoxide(1.54 g) in dry THF was added dropwise with stirring. After 45 mins, thereaction was cooled to −65° C. and the clear oil (780 mg, preparedabove) was added in dry THF dropwise, keeping the temperature between−60° C. and −65° C. The mixture was allowed to warm to room temperatureand after a further 30 mins was quenched with ice/water. The mixture wasextracted with Et₂O (×3) and the combined extracted were washed withbrine, dried over sodium sulphate, evaporated in vacuo, thenre-evaporated in vacuo with toluene to give crude material (3.71 g). Thematerial was purified by normal phase chromatography (ISCO) usingcyclohexane/EtOAc as eluent (0-20%) to give the title compound as aclear oil (581 mg).

¹H NMR (CDCl₃): δ 6.58+5.91 (1H d+d), 4.81+4.45 (1H, dd+dd),4.31-4.23+3.76-3.69+3.52-3.44 (2H, m+m+m), 4.04-3.95 (1H, m), 3.61+3.56(3H, s+s), 1.89-1.77 (1H, m), 1.67-1/32 (5H, m), mixture of isomers inapprox. 60:40 ratio.

Intermediate 71: Tetrahydro-2H-pyran-2-ylacetaldehyde

To a solution of 2-[(E/Z)-2-(Methoxy)ethenyl]tetrahydro-2H-pyran (581mg) in THF (4 mL) was added 2N HCl (4 mL) with stirring. After 2 h themixture was diluted with water and was extracted with DCM (×3). Thecombined organics were washed with dilute brine, dried through ahydrophobic frit and evaporated to give the title compound as a clearoil (528 mg).

¹H NMR (CDCl₃): δ 9.80 (1H, t), 4.01-3.93 (1H, m), 3.88-3.79 (1H, m),3.51-3.43 (1H, m), 2.63-2.54 (1H, m), 2.50-2.42 (1H, m), 1.91-1.80 (1H,m), 1.68-1.48 (4H, m), 1.44-1.31 (1H, m).

Intermediate 72: 2-(Tetrahydro-2H-pyran-2-yl)ethanol

To a stirred solution of tetrahydro-2H-pyran-2-ylacetaldehyde (528 mg)in ethanol (5 mL) was added sodium borohydride granules (156 mg). Themixture was heated at 50° C. for 2 h under nitrogen. After cooling, thesolvent was evaporated and the residue treated with brine. The mixturewas acidified by careful addition of 2N HCl and this mixture wasextracted with DCM (×3). The combined organics were washed with brine,dried using a hydrophobic frit and evaporated to give the title compoundas a clear oil (465 mg).

¹H NMR (CDCl₃): δ 4.02-3.93 (1H, m), 3.83-3.73 (2H, m), 3.57-3.38 (2H,m), 2.83-2.74 (1H, m), 1.88-1.32 (7H, m), hydroxyl proton not seen.

Intermediate 73: 2-(Tetrahydro-2H-pyran-2-yl)ethyl methanesulfonate

2-(Tetrahydro-2H-pyran-2-yl)ethanol (465 mg) was dissolved in dry DCM(10 mL) and triethylamine (996 mg) was added. The stirred solution wascooled in an ice bath under nitrogen and methanesulphonyl chloride (359mg) was added dropwise over 5 mins. The reaction was allowed to warm toroom temperature as the ice bath melted and was left for 16 h. Themixture was then shaken with saturated sodium bicarbonate solution andthe aqueous layer was extracted with DCM (×2). The combined organicextracts were washed with brine, dried using a hydrophobic frit andevaporated to give the title compound as a brown oil (718 mg).

¹H NMR (CDCl₃): δ 4.43-4.27 (2H, m), 4.00-3.92 (1H, m), 3.47-3.35 (2H,m), 3.01 (3H, s), 1.93-1.78 (3H, m), 1.64-1.44 (4H, m), 1.37-1.24 (1H,m).

Intermediate 74:2-Butyloxy-8-methoxy-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-9H-purin-6-amine

A mixture of 2-butoxy-8-methoxy-9H-purin-6-amine trifluoroacetate salt(200 mg) and potassium carbonate (236 mg) in dry DMF (2 mL) were heatedat 60° C. with stirring for 1 h. 2-(Tetrahydro-2H-pyran-2-yl)ethylmethanesulfonate (142 mg) was added and the reaction was continued for16 h at 60° C. The mixture was quenched with water and extracted withEtOAc (×3). The combined organics were washed with water and brine,dried using a hydrophobic frit and evaporated to give crude material(540 mg). The material was purified by normal phase chromatography(ISCO) using 0-20% methanol/EtOAc as eluent to give the title compoundas a white solid (88 mg).

MS calcd for (C₁₇H₂₇N₅O₃)⁺=349

MS found (electrospray): (M+H)⁺=350

¹H NMR (CDCl₃): δ 5.12 (2H, s), 4.29 (2H, t), 4.12 (3H, s), 4.05 (2H,dt), 3.99-3.92 (1H, m), 3.36 (1H, dt), 3.27-3.19 (1H, m), 1.88 (2H,quartet), 1.84-1.66 (5H, m), 1.63-1.37 (4H, m), 1.36-1.23 (1H, m), 0.97(3H, t).

Intermediate 75: (2,2-Dimethyltetrahydro-2H-pyran-4-yl)methanol

A solution of 2,2-dimethyltetrahydro-2H-pyran-4-carbaldehyde (2.5 g) inethanol (30 mL) was cooled (ice bath) and sodium borohydride (665 mg)was added with stirring. The ice bath was removed and the mixture wasallowed to warm to room temperature. After 2 h the reaction was heatedto 50° C. for 1 h, then allowed to cool to room temperature. The solventwas evaporated and the residue was treated with brine, acidified andextracted into DCM (×3). The combined organics were dried through ahydrophobic frit and evaporated to give a clear oil (2.54 g).

¹H NMR (CDCl₃): δ 3.87-3.62 (2H, m), 3.47 (2H, d), 1.99-1.87 (1H, m),1.67-1.55 (3H, m), 1.28-1.06 (8H, m).

Intermediate 76: (2,2-Dimethyltetrahydro-2H-pyran-4-yl)methylmethanesulfonate

(2,2-Dimethyltetrahydro-2H-pyran-4-yl)methanol (2.54 g) was dissolved indry DCM (40 mL) and triethylamine (4.9 mL) was added with stirring. Thesolution was cooled (ice bath) under nitrogen and methanesulphonylchloride (1.77 mL) was added dropwise over 5 mins. The mixture wasallowed to warm slowly to room temperature as the ice bath melted andwas left for 16 h. The mixture was shaken with saturated sodiumbicarbonate solution and the aqueous layer was extracted with DCM (×2).The combined organics were washed with brine, dried using a hydrophobicfrit and evaporated to give the title compound (3.93 g).

¹H NMR (CDCl₃): δ 4.03 (2H, d), 3.82-3.75 (1H, m), 3.68 (1H, dt), 3.02(3H, s), 2.25-2.12 (1H, m), 1.70-1.55 (3H, m), 1.33-1.13 (7H, m).

Intermediate 77: 4-(Bromomethyl)-2,2-dimethyltetrahydro-2H-pyran

A mixture of (2,2-dimethyltetrahydro-2H-pyran-4-yl)methylmethanesulfonate (1.5 g) and anhydrous lithium bromide (2.72 g) inacetone (40 mL) was refluxed under nitrogen for 4 h. The reaction wasallowed to cool and the solvent was evaporated. The residue was treatedwith saturated sodium bicarbonate solution and was extracted with DCM(×3). The combined organics were washed with dilute brine, dried bypassing through a hydrophobic frit and evaporated to give the titlecompound as a brown oil (1.23 g).

¹H NMR (CDCl₃): δ 3.82-3.75 (1H, m), 3.71-3.62 (1H, m), 3.26 (2H, d),2.11-1.98 (1H, m), 1.80-1.66 (2H, m), 1.29-1.08 (8H, m).

Intermediate 78:2-Butyloxy-9-[(2,2-dimethyltetrahydro-2H-pyran-4-yl)methyl]-8-methoxy-9H-purin-6-amine

A mixture of 2-butoxy-8-methoxy-9H-purin-6-amine trifluoroacetate salt(223 mg) and potassium carbonate (264 mg) in dry DMF (2 mL) were heatedat 60° C. under nitrogen with stirring for 1 h.4-(Bromomethyl)-2,2-dimethyltetrahydro-2H-pyran (158 mg) was added andthe reaction was stirred for 16 h at 60° C. The mixture was quenchedwith water and extracted with EtOAc (×3). The combined organics werewashed with water and brine, dried using a hydrophobic frit andevaporated to give a brown oil. The crude material was purified bynormal phase chromatography (ISCO) using 5-20% methanol/EtOAc as eluentto give a pale oil (181 mg). The material was re-purified by normalphase chromatography (ISCO) using 0-15% methanol/EtOAc as eluent to givethe title compound (161 mg).

MS calcd for (C₁₈H₂₉N₅O₃)⁺=363

MS found (electrospray): (M+H)⁺=364

Intermediate 79:N²-Butyl-9-[(2,2-dimethyltetrahydro-2H-pyran-4-yl)methyl]-8-methoxy-9H-purine-2,6-diamine

A mixture of N²-Butyl-8-methoxy-9H-purine-2,6-diamine trifluoroaceticacid salt (200 mg) and potassium carbonate (236 mg) in dry DMF (2 mL)were heated at 60° C. under nitrogen with stirring for 1 h.(2,2-Dimethyltetrahydro-2H-pyran-4-yl)methyl methanesulfonate (152 mg)was added and stirring was continued for 5 h at 50° C. The reaction wascooled to room temperature and stirred for 16 h. Lithium bromide (50 mg)was added and heating was continued for 5 h at 50° C., then 8 h at 90°C. The mixture was quenched with water and extracted with EtOAc (×3).The combined organics were washed with water and brine, dried using ahydrophobic frit and evaporated to give crude material (210 mg). Thiswas purified by C₁₈ reverse phase chromatography (ISCO) using water(0.1% formic acid)-acetonitrile (0.05% formic acid) as eluent (20-60%)to give the title compound (75 mg).

MS calcd for (C₁₈H₃₀N₆O₂)⁺=362

MS found (electrospray): (M+H)⁺=363

¹H NMR (CDCl₃): δ 4.92 (2H, br), 4.60 (1H, t), 4.09 (3H, s), 3.79-3.68(3H, m), 3.65-3.55 (1H, m), 3.43-3.33 (2H, m), 2.36-2.23 (1H, m),1.62-1.53 (2H, m), 1.51-1.13 (12H, m), 0.99-0.91 (3H, m).

Intermediate 80: 3-[(E/Z)-2-methoxyethenyl]tetrahydrofuran

A suspension of (methoxymethyl)triphenylphosphonium chloride (13.71 g)in dry THF (40 mL) was cooled to −40° C. and a solution of potassiumtert-butoxide (4.94 g) in dry THF (40 mL) was added dropwise withstirring. After 45 mins the reaction was cooled to −65° C. Meanwhile, asolution of tetrahydro-3-furancarbaldehyde (8 mL, 50% in water) wastreated with brine to give a cloudy suspension. This was extracted withEt₂O (×3), and the combined organics were dried over sodium sulphate andthe solution was added dropwise to the reaction at −60° C. to −65° C.The mixture was then allowed to warm to room temperature. After 30 minsthe mixture was poured into water and was extracted with Et₂O (×3). Thecombined extracts were washed with brine, dried over sodium sulphate andstripped to give an oil. This was dissolved in a small amount of DCM andwas loaded onto a silica ISCO Cartridge, and solvent was removed underreduced pressure. The crude material was purified by normal phasechromatography (ISCO) using 0-20% EtOAc/cyclohexane as eluent to givethe title compound (460 mg).

¹H NMR (CDCl₃): δ 6.37 (0.75H, d), 5.92 (0.25H, d), 4.67 (0.75H, dd),4.32 (0.25H, dd), 3.97-3.85 (2H, m), 3.84-3.75 (1H, m), 3.60 (0.75H, s),3.52 (2.25H, s), 3.38-3.31 (1H, m), 3.28-3.19 (0.25H, m), 2.81-2.69(0.75H, m), 2.16-2.03 (1H, m), 1.71-1.58 (1H, m), mixture of isomers inapprox. 1:3 ratio.

Intermediate 81: 2-(Tetrahydro-3-furanyl)ethanol

3-[(E/Z)-2-methoxyethenyl]tetrahydrofuran (460 mg) was treated withethanol (2 mL) and 2N HCl (2 mL), and the clear solution was stirred for4 h. The solution was heated at 50° C. for 1 h, then left at roomtemperature for 16 h. The acid was neutralised by adding 2N sodiumhydroxide solution (2 mL) and was diluted with ethanol (3 mL). Sodiumborohydride (136 mg) was added with stirring. After 3 h the solvent wasstripped off and the residue was treated with brine and carefullyacidified with 2N HCl. The mixture was extracted with DCM (×3), waswashed with brine, dried using a hydrophobic frit and evaporated to aclear oil (200 mg). The aqueous layers were combined, saturated withsolid NaCl, extracted with DCM (×3), dried using a hydrophobic frit andevaporated to give a second crop of material (100 mg). This was combinedwith the first crop of clear oil (200 mg), and was purified by normalphase chromatography (ISCO) using 0-20% MeOH/EtOAc as eluent to give thetitle compound (230 mg).

¹H NMR (CDCl₃): δ 3.98-3.83 (2H, m), 3.82-3.64 (3H, m), 3.42-3.35 (1H,m), 2.39-2.27 (1H, m), 2.14-2.03 (1H, m), 1.72-1.64 (2H, m), 1.58-1.51(1H, m), hydroxyl proton not seen.

Intermediate 82: 2-(Tetrahydro-3-furanyl)ethyl methanesulfonate

2-(Tetrahydro-3-furanyl)ethanol (230 mg) was dissolved in dry DCM (5 mL)and triethylamine (0.552 mL) was added. The stirred solution was cooled(ice bath) under nitrogen and methanesulphonyl chloride (0.199 mL) wasadded dropwise over 5 mins. The mixture was allowed to warm slowly toroom temperature as the ice bath melted and was left for 16 h. Themixture was shaken with saturated sodium bicarbonate solution and theaqueous layer was extracted with DCM (×2). The combined organics werewashed with brine, dried using a hydrophobic frit and evaporated to givethe title compound (364 mg).

¹H NMR (CDCl₃): δ 4.32-4.22 (2H, m), 3.98-3.73 (4H, m), 3.44-3.37 (1H,m), 3.03 (3H, s), 2.40-2.30 (1H, m), 2.18-2.06 (1H, m), 1.95-1.79 (2H,m).

Intermediate 83: 3-(2-Bromoethyl)tetrahydrofuran

A mixture of 2-(tetrahydro-3-furanyl)ethyl methanesulfonate (364 mg) andanhydrous lithium bromide (780 mg) were refluxed with stirring inacetone (10 mL) under nitrogen for 4 h. The mixture was allowed to cooland the solvent was evaporated.

The residue was treated with saturated sodium bicarbonate solution andwas extracted with DCM (×3). The combined organics were washed withdilute brine, dried using a hydrophobic frit and evaporated to give thetitle compound (308 mg).

¹H NMR (CDCl₃): δ 3.97-3.84 (2H, m), 3.81-3.74 (1H, m), 3.46-3.36 (3H,m), 2.47-2.36 (1H, m), 2.16-2.06 (1H, m), 2.01-1.92 (2H, m), 1.56-1.49(1H, m).

Intermediate 84:2-Butyloxy-8-methoxy-9-[2-(tetrahydro-3-furanyl)ethyl]-9H-purin-6-amine

A mixture of 2-butoxy-8-methoxy-9H-purin-6-amine trifluoroacetate salt(200 mg) and potassium carbonate (236 mg) in dry DMF (2 mL) was heatedat 60° C. with stirring for 1 h. 3-(2-Bromoethyl)tetrahydrofuran (123mg) was added and the reaction was continued for 2 h. The mixture wasquenched with water and extracted with EtOAc (×3). The combined organicswere washed with water and brine, dried using a hydrophobic frit andevaporated to give an oil (265 mg). The crude material was purified bynormal phase chromatography (ISCO) using 0-15% MeOH/EtOAc as eluent togive the title compound (102 mg).

MS calcd for (C₁₆H₂₅N₅O₃)⁺=335

MS found (electrospray): (M+H)⁺=336

¹H NMR (CDCl₃): δ 5.15 (2H, br), 4.32-4.24 (2H, m), 4.12 (3H, s),3.99-3.94 (2H, m), 3.93-3.82 (2H, m), 3.77-3.69 (1H, m), 3.39 (1H, dd),2.19-2.06 (2H, m), 1.90-1.72 (4H, m), 1.59-1.45 (3H, m), 0.97 (3H, t).

Intermediate 85: Tetrahydro-2H-pyran-3-ylmethyl methanesulfonate

To tetrahydro-2H-pyran-3-ylmethanol (4.92 g) in dry dichloromethane (140ml) at 0° C. and under nitrogen, was added anhydrous triethylamine (13.6ml) in one go, followed by mesyl chloride (4.3 ml) dropwise over 5minutes. The reaction was allowed to warm to room temperature andstirred at this temperature overnight. The reaction was quenched withsaturated aqueous sodium bicarbonate (50 ml). The organic layer wasseparated, passed through a hydrophobic frit to dry and concentrated invacuo to yield a red oil (8.8 g).

¹H NMR (CDCl₃): δ 4.18-4.08 (2H, m), 3.94-3.88 (1H, m), 3.81 (1H, m),3.51-3.43 (1H, m), 3.37-3.31 (1H, m), 3.01 (3H, s), 2.07 (1H, m), 1.85(1H, m), 1.72-1.56 (2H, m), 1.47-1.36 (1H, m).

Intermediate 86: Tetrahydro-2H-pyran-4-ylmethyl methanesulfonate

To tetrahydro-2H-pyran-4-ylmethanol (6.2 g) in dry dichloromethane(226.3 ml) at 0° C. and under nitrogen, was added triethylamine (18.1ml), followed by mesyl chloride (5.4 ml). The reaction was allowed towarm to room temperature and left at this temperature overnight. Thereaction mixture was washed with saturated aqueous sodium bicarbonate(200 ml). The organic layer was separated, passed through a hydrophobicfrit to dry and concentrated in vacuo to yield a light brown lumpy solid(10.17 g).

¹H NMR (DMSO): δ 4.06 (2H, d), 3.85 (2H, m), 3.35-3.25 (1H, m), 3.17(3H, s), 2.50 (1H, m), 2.00-1.87 (1H, m), 1.58 (2H, m), 1.32-1.20 (2H,m).

Intermediate 87:N²-Butyl-8-(methoxy)-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-9H-purine-2,6-diamine

A mixture of N²-butyl-8-methoxy-9H-purine-2,6-diamine trifluoroaceticacid salt (200 mg) and potassium carbonate (236 mg) in dry DMF (2 mL)were heated at 60° C. with stirring for 1 h.2-(Tetrahydro-2H-pyran-2-yl)ethyl methanesulfonate (142 mg) was addedand the reaction was continued for 3 h at 60° C. The mixture wasquenched with water and extracted with EtOAc (×3). The combined organicswere washed with water and brine, dried using a hydrophobic frit andevaporated to give crude material (250 mg). The material was purified byC₁₈ reverse phase chromatography using water (containing 0.1% formicacid)-acetonitrile (containing 0.05% formic acid) as eluent (20-60%) andthe appropriate fractions combined and evaporated to removeacetonitrile. The remaining aqueous mixture was made basic withsaturated sodium hydrogen carbonate, extracted three times withdichloromethane and the combined extracts dried by passing through aphase separation cartridge then evaporated to give 75 mg of materialwhich was recrystallised from ether/light petrol yielding the titlecompound as a solid, 54 mg.

¹H NMR (CDCl₃): δ 4.92 (2H, s), 4.59 (1H, m), 4.10 (3H, s), 3.99 (3H,m), 3.38 (3H, m), 3.25 (1H, m), 1.93-1.37 (11H, m), 1.37-1.23 (1H, m),0.96 (3H, t).

Intermediate 88:N²-Butyl-8-(methoxy)-9-[2-(tetrahydro-3-furanyl)ethyl]-9H-purine-2,6-diamine

A mixture of N²-butyl-8-methoxy-9H-purine-2,6-diamine trifluoroaceticacid salt, (200 mg) and potassium carbonate (236 mg) in dry DMF (2 mL)were heated at 60° C. with stirring for 1 h.3-(2-Bromoethyl)tetrahydrofuran, Intermediate 83 (123 mg) was added andthe reaction was continued for 2 h at 60° C. The mixture was quenchedwith water and extracted with EtOAc (×3). The combined organics werewashed with water and brine, dried using a hydrophobic frit andevaporated to an oil (261 mg). This material was purified by flashchromatography (silica, 5-20% methanol:ethyl acetate) and theappropriate fractions combined and evaporated to give the titlecompound, yield 181 mg.

MS calcd for (C₁₆H₂₆N₆O₂)⁺=334

MS found (electrospray): (M+H)⁺=335

¹H NMR (CDCl₃): δ 4.96 (2H, s), 4.60 (1H, br.t), 4.10 (3H, s), 3.88 (4H,m), 3.73 (1H, m), 3.38 (3H, m), 2.12 (1H, m), 1.85 (3H, m), 1.57 (3H,m), 1.41 (2H, m), 0.95 (3H, t).

Intermediate 89 and Intermediate 90:2-Butoxy-8-methoxy-9-(tetrahydrofuran-3-ylmethyl)-9H-purin-6-amineenantiomers

2-Butoxy-8-methoxy-9-(tetrahydrofuran-3-ylmethyl)-9H-purin-6-amine (0.5gm) was separated into its respective enantiomers using a Chiralpak AD1″×25 cm column, eluting with heptane:IPA 90:10. Fractions containingthe faster eluting material were combined and evaporated to a solid toyield isomer 1, Intermediate 89, 176 mg.

MS calcd for (C₁₅H₂₃N₅O₃)⁺=321

MS found (electrospray): (M+H)⁺=322

1H NMR (CDCl₃): 5.20 (2H, s), 4.28 (2H, t), 4.13 (3H, s), 4.01-3.89 (3H,overlapping m), 3.77 (2H, m), 3.64 (1H, m), 2.85 (1H, m), 1.97 (1H, m),1.81-1.67 (3H, overlapping m), 1.50 (2H, m), 0.96 (3H, t).

Fractions containing the slower eluting material were combined andevaporated to a solid to yield isomer 2, Intermediate 90 178 mg.

MS calcd for (C₁₅H₂₃N₅O₃)⁺=321

MS found (electrospray): (M+H)⁺=322

1H NMR (CDCl₃): 5.15 (2H, s), 4.27 (2H, t), 4.13 (3H, s), 4.01-3.89 (3H,overlapping m), 3.77 (2H, m), 3.64 (1H, m), 2.85 (1H, m), 1.97 (1H, m),1.81-1.67 (3H, overlapping m), 1.50 (2H, m), 0.96 (3H, t).

Intermediate 89, alternative procedure:2-(Butyloxy)-8-(methyloxy)-9-(tetrahydro-3-furanylmethyl)-9H-purin-6-amine(Isomer 1)

A stirring mixture of N²-butyl-8-methoxy-9H-purine-2,6-diaminetrifluoroacetic acid salt (3.25 gm) and potassium carbonate (3.83 gm) indry N,N-dimethylformamide (30 ml) was heated with stirring at 60° C. for1 h. Tetrahydro-3-furanylmethyl methanesulfonate (2 gm, Isomer 1) wasadded and the stirring mixture heated at 90° C. for 3 h. The solvent wasevaporated, water was added and the mixture extracted three times withethyl acetate. The combined extracts were washed with water then brine,dried by passing through a hydrophobic frit and stripped to give anorange solid. This was purified by C₁₈ reverse phase chromatographyusing water (0.1% formic acid)-acetonitrile (0.05% formic acid) aseluent (20-60%) and the appropriate fractions combined and evaporated togive the title compound as a light orange solid, yield 1.56 gm.

MS calcd for (C₁₅H₂₃N₅O₃)⁺=321

MS found (electrospray): (M+H)⁺=322

Intermediate 90, alternative procedure:2-(Butyloxy)-8-(methoxy)-9-(tetrahydro-3-furanylmethyl)-9H-purin-6-amine(Isomer 2)

A stirring mixture of N²-butyl-8-methoxy-9H-purine-2,6-diaminetrifluoroacetic acid salt (3.25 gm) and potassium carbonate (3.83 gm) indry N,N-dimethylformamide (30 ml) was heated with stirring at 60° C. for1 h. Tetrahydro-3-furanylmethyl methanesulfonate (2 gm, Isomer 2) wasadded and the stirring mixture heated at 90° C. for 3 h. The solvent wasevaporated, water was added and the mixture extracted three times withethyl acetate. The combined extracts were washed with water then brine,dried by passing through a hydrophobic frit and stripped to give anorange solid. This was purified by C₁₈ reverse phase chromatographyusing water (0.1% formic acid)-acetonitrile (0.05% formic acid) aseluent (20-60%) and the appropriate fractions combined and evaporated togive the title compound as a light orange solid, yield 2.2 gm.

MS calcd for (C₁₅H₂₃N₅O₃)⁺=321

MS found (electrospray): (M+H)⁺=322

Intermediate 91:2-{[2-(Ethyloxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To a stirred solution of potassium t.butoxide (9.3 g, 82.8 mmol) in1-ethoxy-2-ethanol (70 ml) was added2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (7 g, 27.6 mmol).The mixture was heated to 80-90° C. for 2 h. Then most of the solventwas removed by evaporation under reduced pressure. The residue waspartitioned between water and dichloromethane. The dichloromethane layerwas separated, concentrated to give a light brown solid, which waswashed with petroleum ether, dried in vacuo (7.8 g, 92%).

1H NMR (CDCl₃): 7.86 (1H, s), 6.0-5.8 (2H, br.s), 5.61 (1H, d), 4.49(2H, m), 4.3-4.1 (1H, m), 3.80 (2H, t), 3.8-3.7 (1H, m), 3.60 (2H, t),2.15-1.9 (3H, m), 1.85-1.55 (3H, m), 1.23 (3H, t). Impurity peaks at3.75, 3.55, 1.2, 0.85.

Intermediate 92:8-Bromo-2-{[2-(ethyloxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To a stirred solution of2-{[2-(ethyloxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(7.8 g, 25.4 mmol) in dichloromethane (100 ml) and NBS (5 g, 27.9 mmol)added with stirring. After 2 h, the solvent was removed. The product waspurified through a silica column using petroleum ether: ethyl acetate2:1 as eluent, which was a pale yellow solid (7.8 g, 79.6%).

1H NMR (CDCl₃): 5.9-5.7 (2H, br.s), 5.57 (1H, d), 4.55-4.4 (2H, m),4.2-4.1 (1H, m), 3.78 (2H, t), 3.75-3.6 (1H, m), 3.58 (2H, q), 2.9-3.1(1H, m), 2.15-2.0 (1H, m), 1.9-1.5 (4H, m), 1.21 (3H, t).

Intermediate 93:2-{[2-(Ethyloxy)ethyl]oxy}-8-(methyloxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

Sodium (1.25 g, 54.4 mmol) was dissolved in methanol (40 ml). After 10min,8-bromo-2-{[2-(ethyloxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(7 g, 18 mmol) was added with stirring. The mixture was heated to refluxfor 2 h. The solvent was removed. The residue on a silica column usingDCM:MeOH 100:1 as eluent to give the product as a yellow solid (4.78 g,78.4%).

1H NMR (CD₃OD): 5.6-5.5 (1H, m), 4.55-4.4 (2H, m), 4.18 (3H, s),4.15-4.05 (1H, m), 3.9-3.8 (2H, 2×m), 3.8-3.7 (1H, m), 3.7-3.6 (2H, q),2.9-2.75 (1H, m), 2.15-2.05 (1H, m), 1.9-1.55 (4H, m), 1.25 (3H, t).Exchangeable protons not observed.

Intermediate 94:2-{[2-(Ethyloxy)ethyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetic acid salt

2-{[2-(Ethyloxy)ethyl]oxy}-8-(methyloxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(4.78 g, 14.2 mmol) was dissolved in MeOH (30 ml) and TFA (7.5 ml) wasadded with stirring at 0° C. The mixture was left standing at roomtemperature for 1 day. A white solid was formed. The solid was filteredoff and washed with ethyl acetate and dried in vacuo. This gave product(4 g, 80.5%).

1H NMR (CD₃OD): 4.6-4.55 (2H, m), 4.15 (3H, s), 3.85-3.75 (2H, m), 3.37(2H, q), 1.18 (3H, d). Exchangeable protons not observed.

Intermediate 95:2-(2-Ethoxyethoxy)-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

To a solution of 2-[2-(ethyloxy)ethyl]oxy-8-(methoxy)-9H-purin-6-aminetrifluoroacetic acid salt (500 mg) in dry N,N-dimethylformamide (4.5 ml)at room temperature and under nitrogen was added potassium carbonate(0.75 g) in one go. The reaction was stirred at 60° C. for 1.5 hours.Tetrahydro-2H-pyran-4-ylmethyl methanesulfonate (0.29 g) was added inone portion and the reaction heated at 90° C. for 3 hours. The reactionwas cooled to room temperature and then diluted with ethyl acetate (20ml) and washed with water (15 ml). The organic layer was dried overmagnesium sulphate, filtered and concentrated in vacuo. The product waspurified by C₁₈ reverse phase chromatography using water (containing0.1% formic acid)-acetonitrile (containing 0.05% formic acid) as eluant(10-45%) to afford the title compound as a white solid (240 mg).

MS calcd for (C₁₆H₂₅N₅O₄)⁺=351

MS found (electrospray): (M+H)⁺=352

¹H NMR ((CD₃)₂SO): δ 6.81 (2H, s), 4.27 (2H, m), 4.05 (3H, s), 3.81 (2H,m), 3.73 (2H, d), 3.64 (2H, m), 3.48 (2H, q), 3.22 (2H, m), 2.01 (1H,m), 1.41 (2H, m), 1.23 (2H, m), 1.12 (3H, t).

Intermediate 96:2-{[2-(Ethyloxy)ethyl]oxy}-8-(methoxy)-9-(tetrahydro-2H-pyran-3-ylmethyl)-9H-purin-6-amine

To a solution of 2-{[2-(ethyloxy)ethyl]oxy}-8-(methoxy)-9H-purin-6-aminetrifluoroacetic acid salt (500 mg) in dry N,N-dimethylformamide (6.0 ml)at room temperature and under nitrogen was added potassium carbonate(0.75 g) in one go. The reaction was stirred at 60° C. for 1.5 hours. Asolution of tetrahydro-2H-pyran-3-ylmethyl methanesulfonate (0.29 g) indry N,N-dimethylformamide (1.0 ml) was added in one go and the reactionheated at 90° C. for 2 hours. The reaction was cooled to roomtemperature and then diluted with ethyl acetate (20 ml) and washed withwater (10 ml). The organic layer was concentrated in vacuo. The productwas purified by C₁₈ reverse phase chromatography using water (containing0.1% formic acid)-acetonitrile (containing 0.05% formic acid) as eluant(10-60%) to afford the title compound as a clear viscous oil thatcrystallises at room temperature (245 mg).

MS calcd for (C₁₆H₂₅N₅O₄)⁺=351

MS found (electrospray): (M+H)⁺=352

Intermediate 97:2-{[1-Methyl-2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To a stirred solution of potassium t.butoxide (9.3 g, 82.8 mmol) in1-methoxy-2-propanol (70 ml) was added2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (7 g, 27.6 mmol).The mixture was heated to 80-90° C. for 4 h. Then most of the solventwas removed by evaporation under reduced pressure. The residue waspartitioned between water and dichloromethane. The dichloromethane layerwas separated, concentrated to give a brown oil (7.2 g, 84.7%).

1H NMR (CDCl₃): 7.84 (1H, s), 5.8-5.55 (2H, br.s+1H, m), 5.45-5.3 (1H,m), 4.2-4.05 (1H, m), 3.8-3.6 (2H, 2×m), 3.5-3.42 (1H, m), 3.40 (3H, s),2.1-1.9 (3H, m), 1.8-1.55 (3H, m), 1.35 (3H, dd). Impurity peaks at5.05, 3.38, 1.21, 1.12.

Intermediate 98:8-Bromo-2-{[1-methyl-2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To a stirred solution of2-{[1-methyl-2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(7.2 g, 23.4 mmol) in dichloromethane (100 ml) was added NBS (4.6 g,25.8 mmol). After 4 h, the solvent was removed. The product was purifiedon a silica column using petroleum ether:ethyl acetate 2:1 as eluent.This gave the product (7.3 g, 81.1%).

1H NMR (CDCl₃): 5.9-5.65 (2H, br.s), 5.65-5.55 (1H, m), 5.4-5.2 (1H, m),4.2-4.05 (1H, m), 3.8-3.6 (2H, m), 3.55-3.42 (1H, m), 3.40 (3H, 2×s),2.9-3.1 (1H, m), 2.15-2.0 (1H, m), 1.9-1.5 (4H, m), 1.37 (3H, dd).

Intermediate 99:2-{[1-Methyl-2-(methoxy)ethyl]oxy}-8-(methoxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

Sodium (1.16 g, 50.5 mmol) was dissolved in methanol (40 ml) and8-bromo-2-{[1-methyl-2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(6.5 g, 16.8 mmol) added with stirring. The mixture was heated to refluxfor 2 h. The solvent was removed by evaporation. The residue waspurified on a silica column using DCM: MeOH 150:1 as eluent. This gaveproduct (4.7 g, 82.9%).

1H NMR (CD₃OD): 5.6-5.5 (1H, m), 5.4-5.3 (1H, m), 4.20 (3H, s), 4.2-4.1(1H, m), 3.8-3.6 (2H, 2×m), 3.6-3.5 (1H, m), 3.45 (3H, 2×s), 2.95-2.8(1H, m), 2.2-2.05 (1H, m), 1.9-1.6 (4H, m), 1.40 (3H, dd). Exchangeableprotons not observed.

Intermediate 100:2-{[1-Methyl-2-(methoxy)ethyl]oxy}-8-(methoxy)-9H-purin-6-aminetrifluoroacetic acid salt

TFA (7.5 ml) was added to a solution of2-{[1-methyl-2-(methoxy)ethyl]oxy}-8-(methoxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(4.7 g, 13.9 mmol) in MeOH (30 ml) with stirring. The mixture was leftto stand at room temperature for 1 day. A white solid formed which wasfiltered off and washed with ethyl acetate. This gave product (3.7 g,76.1%)

1H NMR (CD₃OD): 5.55-5.4 (1H, m), 4.16 (3H, s), 3.7-3.55 (2H, m), 3.39(3H, s), 1.40 (3H, d). Exchangeable protons not observed.

Intermediate 101:2-{[1-Methyl-2-(methoxy)ethyl]oxy}-8-(methoxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

To a solution of2-{[1-methyl-2-(methoxy)ethyl]oxy}-8-(methoxy)-9H-purin-6-aminetrifluoroacetic acid salt (500 mg) in dry N,N-dimethylformamide (4.5 ml)at room temperature and under nitrogen was added potassium carbonate(0.75 g) in one go. The reaction was stirred at 60° C. for 1.5 hours.Tetrahydro-2H-pyran-4-ylmethyl methanesulfonate (0.29 g) was added inone go and the reaction heated at 90° C. for 3 hours. The reaction wascooled to room temperature and then diluted with ethyl acetate (20 ml)and washed with water (15 ml). The organic layer was dried overmagnesium sulphate, filtered and concentrated in vacuo. The product waspurified by C₁₈ reverse phase chromatography using water (containing0.1% formic acid)-acetonitrile (containing 0.05% formic acid) as eluant(10-45%) to afford the title compound as a viscous clear oil (260 mg).

MS calcd for (C₁₆H₂₅N₅O₄)⁺=351

MS found (electrospray): (M+H)⁺=352.

¹H NMR ((CD₃)₂SO): δ 6.77 (2H, s), 5.16 (1H, m), 4.05 (3H, s), 3.81 (2H,m), 3.72 (2H, d), 3.48 (2H, m), 3.28 (3H, s), 3.22 (2H, m), 2.01 (1H,m), 1.41 (2H, m), 1.24 (2H, m), 1.21 (3H, d).

Intermediate 102:2-{[1-Methyl-2-(methyloxy)ethyl]oxy}-8-(methoxy)-9-(tetrahydro-2H-pyran-3-ylmethyl)-9H-purin-6-amine

To a solution of2-{[1-methyl-2-(methoxy)ethyl]oxy}-8-(methoxy)-9H-purin-6-aminetrifluoroacetic acid salt (500 mg) in dry N,N-dimethylformamide (6.0 ml)at room temperature and under nitrogen was added potassium carbonate(0.75 g) in one go. The reaction was stirred at 60° C. for 1.5 hours. Asolution of tetrahydro-2H-pyran-3-ylmethyl methanesulfonate (0.29 g) indry N,N-dimethylformamide (1.0 ml) was added in one go and the reactionheated at 90° C. for 2 hours. The reaction was cooled to roomtemperature and then diluted with ethyl acetate (20 ml) and washed withwater (10 ml). The organic layer was concentrated in vacuo. The productwas purified by C₁₈ reverse phase chromatography using water (containing0.1% formic acid)-acetonitrile (containing 0.05% formic acid) as eluant(10-60%) to afford the title compound as a clear viscous oil (300 mg).

MS calcd for (C₁₆H₂₅N₅O₄)⁺=351

MS found (electrospray): (M+H)⁺=352

Intermediate 103: (2-Cyclopropylethyl)amine

To a 1.0M solution of lithium aluminium hydride in diethyl ether (40 ml)at 0° C. was added dropwise concentrated sulphuric acid (1.09 ml) over12 minutes. The reaction was warmed to RT and stirred for 1 hour. Asolution of cyclopropylacetonitrile (1.06 g) in diethyl ether (5 ml) wasadded to dropwise to the reaction over 10 minutes. The reaction washeated to reflux for 2 hours, cooled to 0° C. and quenched with slowaddition of water. A solution of sodium hydroxide (2 g) in water (18 ml)was added and the organic phase decanted from the resulting whiteprecipitate. The precipitate was rinsed with diethyl ether (2×20 ml).The combined organics were concentrated in vacuo (30° C., 300 mbar) toafford the title compound as a colourless oil (1.10 g).

¹H NMR ((CD₃)₂SO): δ 2.58 (2H, t), 1.23 (2H, q), 0.68 (1H, m), 0.36 (2H,m), −0.01 (2H, m). NH₂ protons not observed.

Intermediate 104: Cyclopentylmethylamine

To a 1.0M solution of lithium aluminium hydride in dry diethyl ether (27ml) at RT was added a solution of cyclopentanecarbonitrile (2 g) in drydiethyl ether (10 ml) dropwise over 10 minutes. The purple solution wasstirred at RT for 24 hours. The resulting pink solution was cooled to 0°C. and 5.0M sodium hydroxide solution (10 ml) was added slowly untileffervescence ceased. The reaction was filtered from the whiteprecipitate that had formed. The filtrate was dried over magnesiumsulphate, filtered and concentrated in vacuo (RT, 200 mbar) to affordthe title compound as a clear oil (1.6 g).

¹H NMR ((CD₃)₂SO): δ 2.63 (2H, d), 1.92 (1H, m), 1.77 (2H, m), 1.57 (4H,m), 1.18 (2H, m). NH₂ protons not observed.

Intermediate 105:8-Bromo-N²-(cyclopentylmethyl)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine-2,6-diamine

A solution of2-chloro-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine (150 mg) incyclopentylamine (276 mg) was heated in the microwave at 170° C. for twominutes. The reaction mixture was concentrated in vacuo. To theresulting yellow residue in dry chloroform (2 mL) at room temperature,was added NBS (120 mg) in one go. The reaction was stirred at RT for 10minutes. More NBS (150 mg) was added and the reaction stirred for anadditional 30 minutes at RT. The reaction was concentrated in vacuo andthe product was purified by C₁₈ reverse phase chromatography using water(containing 0.1% formic acid)-acetonitrile (containing 0.05% formicacid) as eluant (20-60%) to afford the title compound as a white solid(40 mg).

MS calcd for (C₁₇H₂₅BrN₆O)⁺=409/410

MS found (electrospray): (M+H)⁺=410/411

Intermediate 106:N²-(Cyclohexylmethyl)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine-2,6-diamine

A solution of2-chloro-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine (150 mg) incyclohexylamine (363 ul) was heated in the microwave at 170° C. for fiveminutes. The crude reaction mixture was subjected to C₁₈ reverse phasechromatography using water (containing 0.1% formic acid)-acetonitrile(containing 0.05% formic acid) as eluant (20-60%) to afford a whitesolid (98 mg).

MS calcd for (C₁₈H₂₈N₆O)⁺=344

MS found (electrospray): (M+H)⁺=345

¹H NMR ((CD₃)₂SO): δ 7.64 (1H, s), 6.54 (2H, s), 6.20 (1H, m), 3.84 (4H,m), 3.21 (2H, m), 3.08 (2H, m), 2.09 (1H, m), 1.78-1.52 (6H, m), 1.40(2H, m), 1.30-1.10 (5H, m), 0.89 (2H, m).

Intermediate 107:8-Bromo-N²-(cyclohexylmethyl)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine-2,6-diamine

To a solution ofN²-(cyclohexylmethyl)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine-2,6-diamine(90 mg) in dry chloroform (1 mL) at room temperature was added NBS (46mg) in one go. The dark brown reaction was stirred at RT for 1 hour. Thereaction was diluted with DCM (15 mL) and washed with water (5 mL). Theorganics were passed through a hydrophobic frit and concentrated invacuo.

MS calcd for (C₁₈H₂₇BrN₆O)⁺=422/424

MS found (electrospray): (M+H)⁺=423/425

Intermediate 108: Tetrahydro-2H-pyran-4-ylmethanol

Methyl tetrahydro-2H-pyran carboxylate (SC/143233, Aldrich) (5.0 g) indry THF (10 mL) was added drop wise to a cooled solution of 1M lithiumaluminium hydride in THF (32 mL), keeping the temperature below 10° C.On completion of the addition, the exotherm was allowed to subsidebefore allowing the reaction mixture to warm to room temperature. Thereaction was then stirred for 2 hours. The reaction was quenched withwater (2 mL) added very carefully and with cooling, followed by 2Nsodium hydroxide (2 mL). To resultant suspension was then added water(100 mL) and then extracted with dichloromethane (100 mL, 3 times). Theorganic layer was separated, combined and dried by passing through ahydrophobic frit. The organic was evaporated under reduced pressure togive colourless mobile oil that was then placed under high vacuo for 30minutes at room temperature. This gave the title compound as colourlessmobile oil (2.4367 g).

1H NMR (CDCl₃): 4.04-3.96 (2H, m), 3.54-3.47 (2H, m), 3.46-3.36 (2H, m),1.82-1.61 (3H, m), 1.57-1.50 (1H, m), 1.40-1.27 (2H, m)

Intermediate 109:2,6-Dichloro-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine

A mixture of tetrahydro-2H-pyran-4-ylmethanol (2.44 g) and2,6-dichloropurine (1.97 g) was dissolved in dry THF (25 mL). To thissolution was added triphenylphosphine (5.51 g), followed by diisopropylazodicarboxylate (4.14 mL) added drop wise. The temperature of thereaction was kept below 43° C. (some cooling with a water bath wasrequired). The reaction was stirred overnight at ambient temperaturebefore being quenched with water (100 mL) and extracted into ethylacetate (50 mL, twice). The separated and combined organic layer wasthen washed with water (100 mL). The organic layer was separated andthen dried by passing through a hydrophobic frit before evaporationunder reduced pressure to give pale yellow viscous oil. The material waspartially purified by silica chromatography (ISCO) using 0-100% ethylacetate: cyclohexane.

The desired product eluted as two peaks. Peak 1 eluted at 70% ethylacetate:cyclohexane. Peak 2 eluted with 100% ethyl acetate.

NMR (CD₃OD) showed both batches were identical with the exception thatthe second peak contained marginally more triphenylphosphine oxide asimpurity.

Peak 1: 1 H NMR (CD₃OD): 8.56 (1H, s), 4.24-4.20 (2H, m), 3.96-3.90 (2H,m), 3.42-3.33 (2H, m), 2.30-2.17 (1H, m), 1.55-1.34 (5H, overlapping m).

[7.69-7.52 (15H, overlapping m)-triphenylphosphine oxide impurity].Title compound:triphenylphosphine oxide impurity (1:0.92).

Peak 2: 1H NMR (CD₃OD): 1H NMR (CD₃OD): 8.56 (1H, s), 4.24-4.20 (2H, m),3.96-3.90 (2H, m), 3.42-3.33 (2H, m), 2.30-2.17 (1H, m), 1.55-1.34 (5H,overlapping m).

[7.69-7.52 (15H, overlapping m)-triphenylphosphine oxide impurity].Title compound:triphenylphosphine oxide impurity (1:0.54).

Both batches were combined to give the title compound (3.0833 g, crude)and triphenylphosphine as impurity

MS calcd for (C₁₁H₁₂Cl₂N₄O)⁺=286, 288, 290

MS found (electrospray): (M+H)⁺=287, 289, 291

Intermediate 110:2-Chloro-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

2,6-dichloro-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine (3.08 g,containing triphenylphosphine oxide) was heated with 2M ammonia in IPA(50 mL) at 50° C., overnight. The reaction mixture was then evaporatedto dryness to give a yellow solid. This material (3.2089 g) wasrecrystallised using methanol (50 mL) and after cooling the resultantsolid was filtered and washed with methanol (5 mL) to give the titlecompound (1.5554 g). The filtrate was evaporated and recrystallised frommethanol (25 mL) and after cooling the resultant solid was filtered togive a second crop (0.2324 g) and was consistent with first batch by NMRand LCMS.

1H NMR (CD₃OD): 8.06 (1H, s), 4.10-4.05 (2H, m), 3.96-3.88 (2H, m),3.41-3.32 (2H, m), 2.23-2.10 (1H, m), 1.53-1.45 (2H, m), 1.43-1.30 (2H,m) (NH₂ exchanged).

MS calcd for (C₁₁H₁₄ClN₅O)⁺=267, 269

MS found (electrospray): (M+H)⁺=268, 270

Intermediate 111:2-[(2-Methylpropyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

2-Chloro-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine (0.20 g)was added to a suspension of 2-methyl-1-propanol (2 mL) and sodiumtert-butoxide (0.288 g). The mixture was heated in a microwave for 30minutes at 105° C. The reaction mixture was washed with water afterdiluting with ethyl acetate (50 mL). The organic was separated and driedby passing through a hydrophobic frit before volatiles were stripped offunder reduced pressure to give a pinkish solid. This material wastriturated with diethyl ether and filtered to give the title compound asa pinkish solid (91.1 mg).

1H NMR ((CD₃)₂SO): 7.89 (1H, s), 7.14 (2H, broad s), 4.02-3.90 (4H, m),3.85-3.76 (2H, m), 3.31-3.13 (2H, m), 2.15-1.92 (2H, slightlyoverlapping m's), 1.43-1.35 (2H, m), 1.29-1.16 (2H, m), 1.00-0.92 (6H,m).

MS calcd for (C₁₅H₂₃N₅O₂)⁺=305

MS found (electrospray): (M+H)⁺=306

Intermediate 112:8-Bromo-2-[(2-methylpropyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

2-[(2-Methylpropyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(88 mg) was dissolved in glacial acetic acid (1.5 mL) before addingsodium acetate (355 mg). The above was then cooled in an ice-bath beforebromine (0.2 mL) which was added gradually. The reaction mixture waswarmed to room temperature before being heated to 70° C. (externaltemperature) for 4 hours. The reaction mixture was quenched with 10%(w/v) sodium thiosulphate solution (to a pale yellow colour with nofurther change) and then the pH was adjusted to 6-7 by the addition of2M sodium hydroxide. This was then extracted into ethyl acetate (20 mL,3 times). The organic layer was separated, combined and dried by passingthrough a hydrophobic frit. The organic layer was evaporated underreduced pressure and then azeotroped with toluene to give the titlecompound as a pale yellow solid (0.10 g). This material then used in thenext stage without the need for purification

1H NMR (CD₃OD): 4.11-4.07 (2H, m), 4.05-4.01 (2H, m), 3.96-3.86 (2H, m),3.40-3.25 (2H, m) (slightly obscured by residual protons CHD₂OD),2.29-2.16 (1H, m), 2.14-2.00 (1H, m), 1.55-1.37 (4H, m), 1.06-0.90 (6H,m) (NH2 exchanged).

MS calcd for (C₁₅H₂₂BrN₅O₂)⁺=383, 385

MS found (electrospray): (M+H)⁺=384, 386

Intermediate 113:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

2-[(2-Cyclopropylethyl)oxy]-8-methoxy-9H-purin-6-amine trifluoroaceticacid salt (0.30 g) was heated with potassium carbonate (anhydrous, 0.46g) in anhydrous DMF (5 mL) at 60° C. for 1 hour. The reaction was cooledto room temperature before 4-(bromomethyl)tetrahydro-2H-pyran (0.16 g)in anhydrous DMF (1 mL) was added. The reaction mixture was then heatedto 50° C. overnight. The reaction was quenched into water (50 mL) andextracted with ethyl acetate (50 mL, 3 times). The organic layer wascombined and washed with brine (50 mL). The organic layer was separatedand dried by passing through a hydrophobic frit before being evaporatedunder reduced pressure to give oil). This material was purified by C₁₈reverse phase chromatography using water (containing 0.1% formicacid)-acetonitrile (containing 0.05% formic acid) as eluent (20-60%).This material was purified by reverse phase chromatography (20-60%acetonitrile: water). This gave the title compound as a white solid(0.1279 g).

1H NMR (CDCl₃): 5.14 (2H, broad s), 4.39-4.32 (2H, m), 4.12 (3H, m),4.00-3.92 (2H, m), 3.85-3.79 (2H, m), 2.19-2.07 (1H, m), 1.80-1.62(representing 2H, m [water underlying]), 1.54-1.34 (4H, m), 0.91-0.81(1H, m), 0.91-0.81 (2H, m), 0.50-0.08 (2H, m), 0.14-0.08 (2H, m).

MS calcd for (C₁₇H₂₅N₅O₃)⁺=347

MS found (electrospray): (M+H)⁺=348

Intermediate 114:2-[(Cyclohexylmethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

Cyclohexylmethanol (4.5784 g) was diluted with 1,2-dimethoxyethane(99%+) (20 mL) before sodium tert-butoxide (3.853 g) was added graduallywith stirring under nitrogen. An exotherm was observed on addition ofsodium tert-butoxide.2-Chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (2.5428 g) wasadded and the resultant mixture was heated to reflux at 93° C.(internal). A further quantity of 1,2-dimethoxyethane (99%+) (20 mL) wasadded to help dissolution and refluxed overnight. The reaction mixturewas dissolved in water (100 mL) and extracted with ethyl acetate (100mL, twice). The combined organic extracts were washed with brine (100mL) before the organic layer was separated and dried by passing througha hydrophobic frit. Evaporated volatiles under reduced pressure and thenazeotroped with toluene (50 mL, twice) to give mobile amber oil. Thismaterial was purified by silica chromatography (ISCO) eluting with0-100% ethyl acetate:cyclohexane). This gave the title compound afterplacing under vacuo as pale yellow foam (1.0364 g) (94% purity by LCMS,6% 2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine) and was usedin next step without further purification.

1H NMR (CDCl₃): 7.85 (1H, s), 5.69-5.61 (1H, m), 5.45 (2H, broad s),4.20-4.07 (3H, overlapping m), 3.82-3.72 (1H, m), 2.14-1.59 (12H,overlapping m), 1.36-1.01 (5H, overlapping m).

MS calcd for (C₁₇H₂₅N₅O₂)⁺=331

MS found (electrospray): (M+H)⁺=332

Intermediate 115:8-Bromo-2-[(cyclohexylmethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

2-[(Cyclohexylmethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(1.0364 g) was dissolved in chloroform (20 mL) and cooled to 0° C.before N-bromosuccinimide (0.5852 g) was added gradually (the reactiontemperature not exceeding 1.9° C. during the addition ofN-bromosuccinimide). The reaction mixture was stirred at ˜2° C. for 15minutes before being warmed to room temperature at which it was stirredfor 6 hours (under nitrogen). Water (100 mL) was added to the reactionmixture and stirred rapidly before the organic layer was separated usinga hydrophobic frit. The organic phase was evaporated under reducedpressure to give dark brown oil. This material was purified by silicachromatography eluting with 0-50% ethyl acetate; cyclohexane to give thetitle compound as a pale yellow solid (0.8200 g).

1H NMR (CDCl₃): 5.64-5.58 (1H, m), 5.50-5.37 (2H, broad s), 4.20-4.06(3H, overlapping m), 3.75-3.66 (1H, m), 3.09-2.97 (1H, m), 2.15-2.06(1H, m), 1.93-1.57 (10H, overlapping m), 1.35-1.01 (5H, overlapping m).

MS calcd for (C₁₇H₂₄BrN₅O₂)⁺=409, 411

MS found (electrospray): (M+H)⁺=410, 412

Intermediate 116:2-[(Cyclohexylmethyl)oxy]-8-(methoxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

8-Bromo-2-[(cyclohexylmethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(0.8151 g) was refluxed with 30% (w/v) sodium methoxide in methanol (1.1mL) diluted with anhydrous methanol (6.0 mL). The suspension wasrefluxed (70° C. external) overnight. The reaction was partitionedbetween ethyl acetate (50 mL) and saturated aqueous ammonium chloridesolution (50 mL). The organic layer was separated and the aqueous layerwas re-extracted with ethyl acetate (50 mL). The organic layers werecombined and washed with brine (50 mL) and separated before then beingdried by passing through a hydrophobic frit. Evaporation under reducedpressure gave crude title compound as foam (0.7132 g) used withoutpurification.

NMR (CDCl₃) consistent but mixture of more than one compound.

MS calcd for (C₁₈H₂₇N₅O₃)⁺=361 observed with other parent ions (e.g.404)

MS found (electrospray): (M+H)⁺=362

Intermediate 117:2-[(Cyclohexylmethyl)oxy]-8-(methyloxy)-9H-purin-6-aminetrifluoroacetate salt

2-[(Cyclohexylmethyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(0.7132 g, crude) was dissolved in methanol (5 mL). To this solution wasadded neat trifluoroacetic acid (0.5 mL). The reaction mixture wasstirred at ambient room temperature for 18 hours. The solvent wasevaporated under reduced pressure and residue triturated with ethylacetate (50 mL). The white resultant solid was filtered, washed usingdiethyl ether (10 mL) and then dried under suction. This gave cleantitle compound as a white solid (0.2799 g).

1H NMR (CD₃OD): 4.29-4.24 (2H, m), 4.14 (3H, s), 1.89-1.66 (6H,overlapping m), 1.39-1.03 (5H, overlapping m) [NH2 and N-9 NH areexchanged].

MS calcd for (C₁₃H₁₉N₅O₂)⁺=277

MS found (electrospray): (M+H)⁺=278

Intermediate 118:2-[(Cyclohexylmethyl)oxy]-8-(methoxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

2-[(Cyclohexylmethyl)oxy]-8-(methoxy)-9H-purin-6-amine trifluoroacetatesalt (0.28 g) was heated with anhydrous potassium carbonate (0.3957 g)in anhydrous DMF (5 mL) under nitrogen for 1 hour at 60° C. (external).The reaction mixture was cooled to room temperature before adding4-(bromomethyl) tetrahydro-2H-pyran (0.14 g) in anhydrous DMF (1 mL).The reaction mixture was heated to 50° C., overnight. The reactionmixture was quenched into water (20 mL) and extracted into ethyl acetate(20 mL, 3 times). The organic layers was separated, combined and thenwashed with brine (20 mL). The organic layer was separated and thendried by passing through a hydrophobic frit. Evaporation under reducedpressure gave pale yellow oil that solidified on standing. This waspurified by C₁₈ reverse phase chromatography using water (containing0.1% formic acid)-acetonitrile (containing 0.05% formic acid) as eluent(30-80%) to give the title compound as a white solid (0.1677 g).

1H NMR (CDCl₃): 5.11 (2H, s), 4.11 (3H, s), 4.10-4.06 (2H, m), 3.99-3.91(2H, m), 3.85-3.79 (2H, m), 3.38-3.29 (2H, m), 2.19-2.06 (1H, m),1.94-1.63 (representing 5H, overlapping water), 1.54-1.00 (10H,overlapping m).

MS calcd for (C₁₉H₂₉N₅O₃)⁺=375

MS found (electrospray): (M+H)⁺=376

Intermediate 119:2-{[2-(Methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(Method A)

2-Methoxyethanol (3.2 mL) was diluted with 1,2-dimethoxyethane (20 mL).To this was added sodium tert-butoxide (3.9 g) gradually and thereaction mixture was stirred under nitrogen until it was homogenous.2-Chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (2.5376 g) wasthen added to the reaction mixture, followed by 1,2-dimethoxyethane (20mL). The reaction mixture was then heated to reflux (110° C., external)overnight. The reaction was quenched with water (100 mL) and extractedwith ethyl acetate (100 mL, twice). The combined organic layers werethen washed with brine (100 mL). The organic layer was then dried bypassing through a hydrophobic frit and then evaporated under reducedpressure (followed by azeotroping with toluene (100 mL, twice)). Thisgave an amber oil that under high vacuo gave gummy foam. This materialwas triturated with diethyl ether (with cooling) until this gave thetitle compound, a pale yellow solid.

1H NMR (CDCl₃): 7.86 (1H, s), 5.66-5.59 (1H, m), 5.47 (2H, broad s),4.54-4.46 (2H, m), 4.19-4.10 (1H, m), 3.80-3.65 (3H, overlapping m),3.43 (3H, s), 2.13-1.93 (3H, overlapping m), 1.81-1.58 (representing 3H,overlapping m, [overlapping water]).

MS calcd for (C₁₃H₁₉N₅O₃)⁺=293

MS found (electrospray): (M+H)⁺=294

Intermediate 119:2-{[2-(Methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(Method B)

Potassium tert.-butoxide (46.5 g, 475 mmol) was added to2-methoxyethanol (200 mL) in 20 min at room temperature, then2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (30 g) was addedand the resulted mixture was heated at 80-90° C. for about 3 h.Evaporation of most of the solvent, to the residue was added 100 ml ofwater, stirred for 1 h at 0° C., filtered and dried. This gave product(30 g, 87%) that was almost identical to that from Intermediate 119,method A.

1H NMR (CDCl₃): 7.84 (1H, s), 5.66-5.59 (1H, m), 4.48 (2H, t), 4.18-4.08(1H, m), 3.80-3.65 (3H, overlapping m), 3.43 (3H, s), 2.1-1.85 (3H, m),1.80-1.55 (3H, m).

Intermediate 120:8-Bromo-2-{[2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

2-{[2-(Methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(1.61 g) was dissolved in chloroform (20 mL) and cooled to 0° C. To thissolution was then added N-bromosuccinimide (1.02 g) gradually, keepingthe temperature at ˜2° C. The reaction was stirred at 2° C. for around15 minutes before being allowed to warm to room temperature. Thereaction mixture was then stirred under nitrogen for 5 hours. Thereaction mixture was quenched with water (100 mL) and stirred rapidlybefore the organic layer was separated using a hydrophobic frit. Theorganic was evaporated under reduced pressure to give a dark brown gum.This material was purified by silica chromatography (ISCO) elutinginitially with 0-70% ethyl acetate:cyclohexane holding isocratic at 70%ethyl acetate; cyclohexane until a minor impurity was eluted. Thegradient was then resumed from 70%-95% ethyl acetate:cyclohexane. Thisgave the title compound as a white solid (1.4489 g)

1H NMR (CDCl₃): 5.65-5.56 (1H, m) 5.44 (2H, broad s), 4.52-4.43 (2H, m),4.20-4.12 (1H, m), 3.79-3.65 (3H, overlapping m), 3.43 (3H, s),3.09-2.96 (1H, m), 2.14-2.03 (1H, m), 1.89-1.56 (representing 4H,overlapping m, [underlying water]).

MS calcd for (C₁₃H₁₈BrN₅O₃)⁺=371, 373

MS found (electrospray): (M+H)⁺=372, 374

Intermediate 121:8-(Methoxy)-2-{[2-(methyloxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

8-Bromo-2-{[2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(1.4489 g) was suspended in dry methanol (11.5 mL) and then treated with25% (w/v) sodium methoxide in methanol (2.5 mL). The reaction mixturewas heated to reflux (65° C., externally) were upon a solution wasobtained. After 4 hours the reaction mixture was concentrated underreduced pressure and saturated aqueous ammonium chloride (100 mL) wasadded. This was then extracted with ethyl acetate (100 mL, twice). Theorganic layers was separated, combined and washed with brine (100 mL).The organic layer was separated and then dried by passing through ahydrophobic frit. This was then evaporated under reduced pressure togive the title compound as a white solid (1.2032 g) after placing underhigh vacuo, overnight.

1H NMR (CDCl₃): 5.53-5.45 (1H, m), 5.16 (2H, broad s), 4.50-4.40 (2H,m), 4.16-4.40 (1H, m) overlapping 4.12 (3H, s), 3.80-3.62 (3H,overlapping m), 3.43 (3H, s), 2.83-2.69 (1H, m), 2.05-1.99 (1H, m),1.82-1.51 (4H, overlapping m).

MS calcd for (C₁₄H₂₁N₅O₄)⁺=323

MS found (electrospray): (M+H)⁺=324

Intermediate 122: 8-(Methoxy)-2-{[2-(methoxy)ethyl]oxy}-9H-purin-6-aminetrifluoroacetate salt

8-(Methoxy)-2-{[2-(methyloxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(1.2032 g) was dissolved in methanol (10 mL) which was treated with neattrifluoroacetic acid (1 mL) and then stirred for 2 days. The reactionmixture was evaporated under reduced pressure and the resultant solidsuspended in ethyl acetate (25 mL) before being filtered to give thetitle compound (1.1310 g) as a white solid.

1H NMR ((CD₃)₂SO): 7.50 (2H, broad s), 4.42-4.34 (2H, m), 4.04 (3H, s)3.67-3.61 (2H, m), 3.30 (3H, s) (N9 proton not observed).

MS calcd for (C₉H₁₃N₅O₃)⁺=239

MS found (electrospray): (M+H)⁺=240

Intermediate 123:8-(Methoxy)-2-{[2-(methyloxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

8-(Methoxy)-2-{[2-(methoxy)ethyl]oxy}-9H-purin-6-amine trifluoroacetatesalt (0.30 g) was heated with anhydrous potassium carbonate (0.4698 g)in anhydrous DMF (5 mL) at 60° C. for 1 hour. The reaction mixture wascooled to room temperature before 4-(bromomethyl) tetrahydro-2H-pyran(0.1669 g) was added in anhydrous DMF (1 mL). The reaction mixture wasthen stirred overnight at 50° C. The reaction mixture was quenched intowater (20 mL) and extracted into ethyl acetate (20 mL, 3 times). Theseparated, combined organic layers were then washed with brine (20 mL).The separated organic layer was dried by passing through a hydrophobicfrit before being evaporated under reduced pressure to give pale yellowoil which solidified on standing. This was purified by C₁₈ reverse phasechromatography using water (containing 0.1% formic acid)-acetonitrile(containing 0.05% formic acid) as eluent (10-45%) to give the titlecompound as a white solid (0.1454 g).

1H NMR (CDCl₃): 5.12 (2H, broad s), 4.47-4.41 (2H, m), 4.12 (3H, s),4.00-3.91 (2H, m), 3.85-3.73 (4H, partially overlapping m), 3.43 (3H,s), 3.38-3.28 (2H, m), 2.18-2.06 (1H, m), 1.53-1.33 (4H, overlapping m).

MS calcd for (C₁₅H₂₃N₅O₄)⁺=337

MS found (electrospray): (M+H)⁺=338

Intermediate 124:8-(Methoxy)-2-{[2-(methyloxy)ethyl]oxy}-9-(tetrahydro-3-furanylmethyl)-9H-purin-6-amine

8-(Methoxy)-2-{[2-(methoxy)ethyl]oxy}-9H-purin-6-amine trifluoroacetatesalt (0.30 g) was dissolved in dry DMF (5 mL). To this was addedanhydrous potassium carbonate (0.47 g) and then heated to 60° C. for 1.5hours. The reaction mixture was cooled to room temperature andtetrahydro-3-furanylmethyl methanesulfonate (0.168 g) was added. Thereaction mixture was then heated to 90° C. for 3.5 hours. The reactionmixture was then quenched into water (100 mL) and extracted into ethylacetate (50 mL, 3 times). The organic was separated and dried by passingthrough a hydrophobic frit and then evaporated under reduced pressure togive a glassy solid. This was purified by C₁₈ reverse phasechromatography using water (containing 0.1% formic acid)-acetonitrile(containing 0.05% formic acid) as eluent (10-45%). This gave the titlecompound as a white solid (0.1233 g).

1H NMR (CDCl₃): 5.46 (2H, broad s), 4.48-4.39 (2H, m), 4.12 (3H, s),4.01-3.87 (3H, overlapping m), 3.79-3.70 (4H, overlapping m), 3.65-3.59(1H, m), 3.43 (3H, s), 2.91-2.78 (1H, m), 2.02-1.90 (1H, m), 1.76-1.64(1H, m).

MS calcd for (C₁₄H₂₁N₅O₄)⁺=323

MS found (electrospray): (M+H)⁺=324

Intermediate 125:2-[(Tetrahydro-2-furanylmethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

Tetrahydrofurfuryl alcohol (4.09 g) was diluted with 1,2-dimethoxyethane(20 mL). To this solution was added sodium tert-butoxide (3.84 g)gradually. The resultant reaction mixture was stirred until homogeneous(orange solution) before2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (2.53 g) wasadded. The reaction mixture was then heated to 110° C. (external)overnight under nitrogen. The reaction mixture was quenched with water(100 mL) and extracted with ethyl acetate (100 mL, 3 times). The organiclayer was separated, combined and then dried by passing through ahydrophobic frit. This was evaporated under reduced pressure and theresultant material was then purified by silica chromatography elutingwith 0-100% ethyl acetate:cyclohexane followed by methanol. An ISCO pumpfault was detected whilst eluting with methanol, this line carried ethylacetate previously and it was not known if the fault existed wheneluting with ethyl acetate:cyclohexane. The appropriate fractions wereevaporated to give the title compound as a solid (1.7258 g). Thismaterial was used in the next stage without further purification.

1H NMR (CDCl₃): 7.87 (1H, m), 6.69 (2H, broad m), 5.68-5.54 (1H, m),4.45-4.36 (1H, m), 4.35-4.21 (2H. overlapping m), 4.17-4.08 (1H, m),3.98-3.89 (1H, m), 3.85-3.68 (2H, overlapping m), 2.15-1.55 (10H,overlapping m).

Intermediate 126:8-Bromo-2-[(tetrahydro-2-furanylmethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

2-[(Tetrahydro-2-furanylmethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(1.7202 g) was dissolved in chloroform (15 mL) and cooled to ˜1° C.before N-bromosuccinimide (1.056 g) was added keeping the reactiontemperature below 2° C. The reaction mixture was then stirred at ˜1° C.for 30 minutes before allowing to warm to room temperature were upon thereaction mixture was stirred for 3 hours. The reaction mixture was thenstood overnight at room temperature before being partitioned betweenwater (50 mL) and the organic phase separated using a hydrophobic frit.The organic phase was evaporated under reduced pressure to give a browngum which was purified using silica chromatography (ISCO) eluting with0-100% ethyl acetate: cyclohexane. This gave the title compound as awhite foam solid (1.3748 g).

1H NMR (CDCl₃): 5.63-5.56 (1H, m), 5.43 (2H, broad s), 4.45-4.36 (1H,m), 4.34-4.10 (3H, overlapping m), 4.98-3.89 (1H, m), 3.85-3.77 (1H, m),3.74-3.66 (1H, m), 3.09-2.97 (1H, m), 2.15-1.56 (representing 9H[overlapping water])

MS calcd for (C₁₅H₂₀BrN₅O₃)⁺=397, 399

MS found (electrospray): (M+H)⁺=398, 400

Intermediate 127:8-(Methoxy)-2-[(tetrahydro-2-furanylmethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

8-Bromo-2-[(tetrahydro-2-furanylmethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(1.3748 g) was dissolved in methanol (10.2 mL) and treated with 25%(w/v) sodium methoxide in methanol (2.2 mL). This was heated to refluxunder nitrogen for 3.5 hours. The reaction mixture was evaporated underreduced pressure to dryness and saturated ammonium chloride solution wasadded (100 mL). This was then extracted with ethyl acetate (100 mL, 3times). The organic layers were combined and washed with brine (100 mL)and then dried by passing through a hydrophobic frit after separatingthe aqueous layer. The organic was evaporated under reduced pressure togive the title compound as white foam (1.1614 g) and used in the nextstage without requiring purification.

1H NMR (CDCl₃): 5.52-5.46 (1H, m), 5.15 (2H, broad s), 4.43-4.36 (1H,m), 4.33-4.26 (1H, m), 4.23-4.17 (1H, m), 4.16-4.09 (1H, m overlapping4.13 (3H, s)), 3.97-3.90 (1H, m), 3.84-3.76 (1H, m), 3.73-3.65 (1H, m),2.83-2.71 (1H, m), 2.13-1.53 (representing 9H, overlapping m[overlapping water]).

MS calcd for (C₁₆H₂₃N₅O₄)⁺=349

MS found (electrospray): (M+H)⁺=350

Intermediate 128:8-(Methoxy)-2-[(tetrahydro-2-furanylmethyl)oxy]-9H-purin-6-aminetrifluoroacetate salt

8-(Methoxy)-2-[(tetrahydro-2-furanylmethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(1.1614 g) was dissolved in methanol (20 mL) and treated with neattrifluoroacetic acid (2 mL). The reaction mixture was stirred for 24hours to give a white suspension. The reaction mixture was thenevaporated to dryness under reduced pressure. The resultant white solidwas suspended using ethyl acetate (10 mL) and then isolated byfiltration, washing with ethyl acetate (2 mL). The solid was air-driedunder suction and then dried further under vacuo at 50° C. This gave thetitle compound as a white solid (1.0602 g).

1H NMR ((CD₃)₂SO): 7.76 (2H, broad s), 4.35-4.11 (3H, overlapping m),4.05 (3H, s), 3.82-3.73 (1H, m), 3.73-3.63 (1H, m), 2.05-1.77 (3H,overlapping m), 1.70-1.59 (1H, m) (N-9 NH not apparent fromspectrum-indication of extremely broad signal at 12.7 ppm (but could beartefact of FT)).

MS calcd for (C₁₁H₁₅N₅O₃)⁺=265

MS found (electrospray): (M+H)⁺=266

Intermediate 129:8-(Methoxy)-2-[(tetrahydro-2-furanylmethyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

8-(Methoxy)-2-[(tetrahydro-2-furanylmethyl)oxy]-9H-purin-6-aminetrifluoroacetate salt (0.30 g) was dissolved in dry DMF (5 mL). To thissolution was added anhydrous potassium carbonate (0.4376 g) and then thereaction mixture was heated to 60° C. under nitrogen for 1 hour. Thereaction mixture was then cooled to room temperature before addingtetrahydro-2H-pyran-4-ylmethyl methanesulfonate (0.1690 g) and then theresultant reaction mixture was heated to 90° C. for 2.5 hours. Thereaction mixture was cooled and then quenched with water (50 mL),followed by extraction into ethyl acetate (50 mL, 3 times). Afterseparating, the organic layers were combined and dried by passingthrough a hydrophobic frit. Evaporation under reduced pressure gavemobile oil which was then purified by C₁₈ reverse phase chromatographyusing water (containing 0.1% formic acid)-acetonitrile (containing 0.05%formic acid) as eluent (10-45%). This gave the title compound as a whitesolid (0.1560 g).

1H NMR (CDCl₃): 5.17 (2H, broad s), 4.40-4.26 (2H, close m), 4.23-4.17(1H, m), 4.11 (3H, s), 3.99-3.89 (3H, overlapping m), 3.84-3.76 (3H,overlapping m), 3.37-3.29 (2H, m), 2.18-1.66 (representing 5H[underlying water peak]), 1.52-1.33 (4H, overlapping m).

MS calcd for (C₁₇H₂₅N₅O₄)⁺=363

MS found (electrospray): (M+H)⁺=364

Intermediate 130: Ethyl (2E)-3-(5,6-dihydro-2H-pyran-3-yl)-2-propenoate

To 5,6-dihydro-2H-pyran-3-carbaldehyde (5.0 g) in dry dichloromethane(150 ml) at 0° C., was added carbethoxymethylene-triphenylphosphorane(15.53 g). The reaction was allowed to warm to room temperature andstirred overnight. The reaction was diluted with dichloromethane (150ml) and washed with water (150 ml) and a saturated aqueous solution ofbrine (150 ml). The organic layer was dried by passing through ahydrophobic frit and concentrated in vacuo. to afford a yellow oil. Theproduct was purified by silica chromatography (120 g) (ISCO) using agradient elution of 0-10% cyclohexane:ethyl acetate to afford the titlecompound as a clear oil (5.59 g).

¹H NMR (CDCl₃): δ 7.27 (1H, t), 6.33 (1H, m), 5.67 (1H, d), 4.35 (2H,m), 4.26 (2H, q), 3.84 (2H, t), 2.39 (2H, m), 1.35 (3H, t).

Intermediate 131: Ethyl 3-(tetrahydro-2H-pyran-3-yl)propanoate

A solution of ethyl (2E)-3-(5,6-dihydro-2H-pyran-3-yl)-2-propenoate (3g) and palladium on carbon (170 mg, 10%, wet) in ethyl acetate (75 ml)was hydrogenated at atmospheric pressure and room temperature. Thehydrogen uptake (˜825 ml) was complete after 30 minutes. The catalystwas filtered through celite and the filtrate concentrated in vacuo. toafford a pale yellow oil (2.90 g). The above was repeated in the exactsame fashion with a second batch. Hence a solution of ethyl(2E)-3-(5,6-dihydro-2H-pyran-3-yl)-2-propenoate (2.59 g) and palladiumon carbon (147 mg, 10% wet) in ethyl acetate (65 ml) was hydrogenated atatmospheric pressure and room temperature. The hydrogen uptake (˜715 ml)was complete after 15 minutes. The catalyst was filtered through celiteand the filtrate concentrated in vacuo. to afford a pale yellow oilwhich was combined with that of the first batch (5.34 g). This waspurified by silica chromatography (120 g) (ISCO) using a gradientelution of 0-10% cyclohexane:ethyl acetate to afford the title compoundas a clear oil (4.61 g).

¹H NMR (CDCl₃): δ 4.13 (2H, q), 3.86 (2H, m), 3.35 (1H, m), 3.06 (1H,m), 2.31 (2H, m), 1.87 (1H, m), 1.64-1.41 (5H, m), 1.26 (3H, t), 1.15(1H, m).

Intermediate 132: 3-(Tetrahydro-2H-pyran-3-yl)-1-propanol

To a stirred solution of lithium aluminium hydride (24.8 ml, 1.0M indiethyl ether) in dry diethyl ether (77 ml) at 0° C. was added asolution of ethyl 3-(tetrahydro-2H-pyran-3-yl)propanoate (4.61 g) in drydiethyl ether (77 ml) dropwise over 20 minutes. After 15 minutes at 0°C. the reaction mixture was warmed to room temperature and stirred for afurther nine hours. The reaction was quenched by the dropwise additionof water over a period of one hour, whilst cooled over ice. Theresulting solids were filtered from the mixture and washed with diethylether. The organic layer was decanted off from the aqueous layer, driedover magnesium sulphate, filtered and concentrated in vacuo. to give aclear oil (3.33 g). The product was purified by silica chromatography(40 g) (ISCO) using a gradient elution of 0-50% cyclohexane:ethylacetate to afford the title compound as a clear oil (2.64 g).

¹H NMR (CDCl₃): δ 3.87 (2H, m), 3.64 (2H, m), 3.35 (1H, m), 3.05 (1H,m), 1.88 (1H, m), 1.66-1.51 (5H, m), 1.39 (1H, t), 1.31-1.08 (3H, m).

Intermediate 133: 3-(Tetrahydro-2H-pyran-3-yl)propyl methanesulfonate

To a solution of 3-(tetrahydro-2H-pyran-3-yl)-1-propanol (2.64 g) in drydichloromethane (78 ml) at 0° C. was added triethylamine (6.21 ml)followed by mesyl chloride (1.85 ml). The reaction mixture was allowedto warm to room temperature as the ice melted and allowed to stir forthree hours. The reaction mixture was washed with sodium hydrogencarbonate. The organic layer was separated, dried by passing through ahydrophobic frit and concentrated in vacuo. to give a yellow oil (4.42g). The product was purified by silica chromatography (80 g) (ISCO)using a gradient elution of 0-50% cyclohexane:ethyl acetate to affordthe title compound as a clear oil (3.79 g).

¹H NMR (CDCl₃): δ 4.22 (2H, t), 3.86 (2H, m), 3.36 (1H, m), 3.07 (1H,m), 3.01 (3H, s), 1.87 (1H, m), 1.82-1.69 (2H, m), 1.65-1.54 (3H, m),1.36-1.10 (3H, m).

Intermediate 134:N²-Butyl-8-(methoxy)-9-[3-(tetrahydro-2H-pyran-3-yl)propyl]-9H-purine-2,6-diamine

To a solution of N²-butyl-8-methoxy-9H-purine-2,6-diaminetrifluoroacetic acid salt (300 mg) in dry N,N-dimethylformamide (5.3 ml)was added potassium carbonate (474 mg). The reaction was stirred at 60°C. for ninety minutes. The reaction was cooled and3-(tetrahydro-2H-pyran-3-yl)propyl methanesulfonate (209 mg) was addedand the reaction heated at 90° C. for three hours. The reaction wascooled, diluted with ethyl acetate and washed with water (2×). Theorganic layer was separated, dried over magnesium sulphate, filtered andconcentrated in vacuo. to afford a yellow oil. The product was purifiedby C₁₈ reverse phase chromatography (43 g) (ISCO) using water (0.1%formic acid)-acetonitrile (0.05% formic acid) as eluant (30-80%) toafford the title compound as a yellow oily residue (198 mg).

MS calcd for (C₁₈H₃₀N₆O₂)⁺=362

MS found (electrospray): (M+H)⁺=363

¹H NMR (DMSO): δ 6.23 (2H, s), 6.01 (1H, t), 3.99 (3H, s), 3.77-3.67(4H, m), 3.26-3.15 (3H, m), 2.91 (1H, m), 1.76 (1H, m), 1.71-1.60 (2H,m), 1.54-1.40 (5H, m), 1.36-1.26 (2H, m), 1.16-0.96 (3H, m), 0.88 (3H,m).

Intermediate 135:9-(Tetrahydro-2H-pyran-2-yl)-2-[(tetrahydro-2H-pyran-2-ylmethoxy]-9H-purin-6-amine

Tetrahydropyran-2-methanol (ex. Aldrich) (4.66 g) was diluted with1,2-dimethoxyethane (20 mL). Added gradually sodium tert-butoxide (3.85g) to the above and stirred until homogeneous (orange solution).2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (2.54 g) wasadded to the above and then heated to reflux (110° C., external),overnight and under nitrogen. The reaction mixture was quenched intowater (100 mL) and extracted using ethyl acetate (100 mL, 3 times). Theorganic phase was separated and then passed through a hydrophobic frit.Evaporation under reduced pressure gave a gum that was then purified byISCO (120 g, SiO₂) eluting with 0-50% methanol: DCM to give the titlecompound as a pale yellow foam (2.1732 g).

MS calcd for (C₁₆H₂₃N₅O₃)⁺=333

MS found (electrospray): (M+H)⁺=334

¹H NMR (CDCl₃): 7.85 (1H, s), 5.66-5.49 (overlapping 1H, m and 2H, broads), 4.41-4.34 (1H, m), 4.25-4.19 (1H, m), 4.18-4.11 (1H, m), 4.06-4.00(1H, m), 3.78-3.69 (2H, m), 3.54-3.45 (1H, m), 2.12-1.83 (4H,overlapping m), 1.83-1.36 (8H, overlapping m).

Intermediate 136:8-Bromo-9-(tetrahydro-2H-pyran-2-yl)-2-[(tetrahydro-2H-pyran-2-ylmethoxy]-9H-purin-6-amine

To a solution of9-(tetrahydro-2H-pyran-2-yl)-2-[(tetrahydro-2H-pyran-2-ylmethoxy]-9H-purin-6-amine(2.17 g) in dry chloroform (23.5 ml), cooled to 0° C., was addedN-bromosuccinimide (1.22 g). The reaction was allowed to return to roomtemperature and stirred for 4 hours. The reaction was diluted with DCM(50 ml) and washed with water (50 ml) and then brine (50 ml). Theorganic layer was separated, dried by passing through a hydrophobicfrit, and concentrated in vacuo. This afforded the title product as abrown foamy solid (2.76 g).

MS calcd for (C₁₆H₂₂BrN₅O₃)⁺=412, 413

MS found (electrospray): (M+H)⁺=413, 414

Intermediate 137:8-(Methoxy)-9-(tetrahydro-2H-pyran-2-yl)-2-[(tetrahydro-2H-pyran-2-ylmethoxy]-9H-purin-6-amine

To a solution of8-bromo-9-(tetrahydro-2H-pyran-2-yl)-2-[(tetrahydro-2H-pyran-2-ylmethoxy]-9H-purin-6-amine(2.76 g) in dry methanol (22.6 ml) at room temperature, was added sodiummethoxide (4.6 ml, 25% wt. methanol). The reaction was heated to refluxfor 4 hours. The reaction was cooled and concentrated in vacuo to yieldan orange residue. This was taken up in ammonium chloride solution (100ml) and extracted with ethyl acetate (100 ml). The organic layer wasseparated and washed with water (50 ml). The organic layer was driedover magnesium sulfate, filtered and concentrated in vacuo. Thisafforded the title compound as an orange foamy solid (2.06 g).

MS calcd for (C₁₇H₂₅N₅O₄)⁺=363

MS found (electrospray): (M+H)⁺=364

Intermediate 138:8-(Methoxy)-2-[(tetrahydro-2H-pyran-2-ylmethoxy]-9H-purin-6-aminetrifluoroacetate salt

To a solution of8-(methoxy)-9-(tetrahydro-2H-pyran-2-yl)-2-[(tetrahydro-2H-pyran-2-ylmethoxy]-9H-purin-6-amine(2.06 g) in dry methanol (20.6 ml) was added trifluoroacetic acid (2.06ml). The reaction was stirred at room temperature for 24 hours. Thereaction mixture was concentrated in vacuo and the resulting residuetriturated in diethyl ether. This resulted in an off-white solidfollowing filtration (1.59 g).

MS calcd for (C₁₂H₁₇N₅O₃)⁺=279

MS found (electrospray): (M+H)⁺=280

Intermediate 139:8-(Methoxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-2-[(tetrahydro-2H-pyran-2-ylmethoxy]-9H-purin-6-amine

To a solution of8-(methoxy)-2-[(tetrahydro-2H-pyran-2-ylmethoxy]-9H-purin-6-aminetrifluoroacetate salt (1.59 g) in dry N,N-dimethylformamide (25 ml) wasadded potassium carbonate (2.24 g). The reaction was stirred at 60° C.for 1.5 hours. The reaction was cooled andtetrahydro-2H-pyran-4-ylmethyl methanesulfonate (866 mg) was added. Thereaction was stirred at 90° C. for 5 hours. The reaction was cooled andtaken up in ethyl acetate and washed twice with water. The organic layerwas separated, dried over magnesium sulphate, filtered and concentratedin vacuo to yield a yellow solid. The product was purified by C₁₈reverse phase chromatography using water (containing 0.1% formicacid)-acetonitrile (containing 0.05% formic acid) as eluant (20-50%) toafford the title compound as an off-white solid (704 mg).

MS calcd for (C₁₈H₂₇N₅O₄)⁺=377

MS found (electrospray): (M+H)⁺=378

Intermediate 140:2-({2-[(1-Methylethyl)oxy]ethyl}oxy)-8-(methoxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine

To a solution of2-({2-[(1-methylethyl)oxy]ethyl}oxy)-8-(methoxy)-9H-purin-6-aminetrifluoroacetate salt (400 mg) in dry N,N-dimethylformamide (6.4 ml) wasadded potassium carbonate (579 mg). The reaction was stirred at 60° C.for 1.5 hours. The reaction was cooled andtetrahydro-2H-pyran-4-ylmethyl methanesulfonate (224 mg) was added. Thereaction was stirred at 90° C. for 4 hours. The reaction was cooled andtaken up in ethyl acetate and washed twice with water. The organic layerwas separated, dried over magnesium sulphate, filtered and concentratedin vacuo to yield a yellow oil (432 mg). The product was purified by C₁₈reverse phase chromatography using water (containing 0.1% formicacid)-acetonitrile (containing 0.05% formic acid) as eluant (20-50%) toafford the title compound as a clear viscous oil (166 mg).

MS calcd for (C₁₇H₂₇N₅O₄)⁺=365

MS found (electrospray): (M+H)⁺=366

Intermediate 141:5-{4-[(Phenylmethyl)oxy]-1-buten-1-yl}-3,6-dihydro-2H-pyran

To a suspension of (3-benzyloxypropyl)triphenylphosphonium bromide (9.90g) in dry tetrahydrofuran (30.5 ml) at −15° C. was added butyllithium(8.06 ml, 2.5M in hexanes) dropwise to give a dark orange solution. Thereaction temperature was increased to 0° C. and stirring was continuedfor 30 minutes. A solution of 5,6-dihydro-2H-pyran-3-carbaldehyde (2.26g) in dry tetrahydrofuran (3 ml) was added dropwise at 0° C. Thereaction mixture was stirred at room temperature for 20 hours. Thereaction mixture was filtered through celite and washed with diethylether. The filtrate was concentrated in vacuo to give an orange oil. Theproduct was purified by silica chromatography using a gradient elutionof 0-25% ethyl acetate/cyclohexane to afford the title compound as acolourless oil (2.04 g).

¹H-NMR (CDCl₃): Mixture of cis and trans δ 7.40-7.27 (5H, m), 6.02(0.60H, d), 5.76 (1.36H, m), 5.49-5.37 (1H, m), 4.53 (2H, m), 4.29(1.23H), 4.22 (0.74H, m), 3.77 (2H, t), 3.51 (2H, m), 2.52 (0.78H, m),2.40 (1.29H, m), 2.24 (2H, m).

Intermediate 142: 4-(Tetrahydro-2H-pyran-3-yl)-1-butanol

A solution of5-{4-[(phenylmethyl)oxy]-1-buten-1-yl}-3,6-dihydro-2H-pyran (2.03 g) and10% palladium on carbon (88 mg) in ethyl acetate (83 ml) washydrogenated at atmospheric pressure and room temperature. Hydrogenuptake (˜500 ml) was complete after 15 hours. The catalyst was filteredthrough celite and the filtrate concentrated in vacuo to afford acolourless oil. Analysis by 1H-NMR showed that the benzyl group waspresent in the majority of the compound. Hydrogenation was continuedunder the same conditions for a further 24 hours with additionalhydrogen uptake of ˜300 ml. The catalyst was filtered through celite andthe filtrate concentrated in vacuo to afford the title compound as acolourless oil (1.21 g).

¹H-NMR (CDCl₃): δ 3.86 (2H, m), 3.63 (2H, t), 3.34 (1H, m), 3.04 (1H,t), 1.86 (1H, m), 1.75 (1H, s), 1.66-1.47 (5H, m), 1.45-1.27 (2H, m),1.26-1.06 (3H, m).

Intermediate 143: 4-(Tetrahydro-2H-pyran-3-yl)butyl methanesulfonate

To a solution of 4-(tetrahydro-2H-pyran-3-yl)-1-butanol (1.20 g) in drydichloromethane (30.3 ml), cooled to 0° C., was added triethylamine(2.43 ml) and methanesulphonyl chloride (0.77 ml) to give a yellowsolution. The reaction mixture was stirred at room temperatureovernight. The reaction mixture was washed with a saturated aqueoussolution of sodium hydrogen carbonate (25 ml). The organic layer wasseparated, dried by passing through a hydrophobic frit and concentratedin vacuo to afford a yellow oil (1.80 g). The product was purified bysilica chromatography using a gradient elution of 0-40% ethylacetate/cyclohexane to afford the title compound as a yellow oil (1.58g).

¹H-NMR (CDCl₃): δ 4.23 (2H, t), 3.86 (2H, m), 3.35 (1H, m), 3.05 (1H,m), 3.01 (3H, s), 1.86 (1H, m), 1.79-1.67 (2H, m), 1.64-1.52 (3H, m),1.47-1.34 (2H, m), 1.28-1.05 (3H, m).

Intermediate 144:N²-butyl-8-(methoxy)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-9H-purine-2,6-diamine

To a solution of N²-butyl-8-(methoxy)-9H-purine-2,6-diamine (250 mg) indry N,N-dimethylformamide (4.46 ml) at room temperature was addedpotassium carbonate (395 mg). The reaction mixture was stirred at 60° C.for 90 min. The reaction was cooled to room temperature and4-(tetrahydro-2H-pyran-3-yl)butyl methanesulfonate (186 mg) was addedand the reaction stirred at 90° C. for 2 hours. The reaction mixture wastaken up in ethyl acetate (50 ml) and washed with water (2×50 ml). Theorganic layer was separated, dried over magnesium sulfate, filtered andconcentrated in vacuo to give an orange oil (366 mg). The product waspurified by C₁₈ reverse phase chromatography using water (containing0.1% formic acid)-acetonitrile (containing 0.05% formic acid) as eluant(30-70%) to afford the title compound as an orange gum (172 mg).

MS calcd for (C₁₉H₃₂N₆O₂)⁺=376

MS found (electrospray): (M+H)⁺=377

Intermediate 145:N²-(2-Cyclopropylethyl)-9-(tetrahydro-2H-pyran-2-yl)-9H-purine-2,6-diamine

To a suspension of2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (3.49 g) inethylene glycol (17 ml) at room temperature was addedcyclopropylethylamine (4.69 g). The reaction mixture was heated to 120°C. with reflux condenser overnight, resulting in a yellow/brownsolution. The reaction was allowed to cool, taken up in ethyl acetate(100 ml) and washed with water (2×100 ml). The organic layer wasseparated, dried over magnesium sulfate, filtered and concentrated invacuo to give a dark brown gum (4.17 g)

MS calcd for (C₁₅H₂₂N₆O)⁺=302

MS found (electrospray): (M+H)⁺=303

Intermediate 146:8-Bromo-N²-(2-cyclopropylethyl)-9-(tetrahydro-2H-pyran-2-yl)-9H-purine-2,6-diamine

To a solution ofN²-(2-cyclopropylethyl)-9-(tetrahydro-2H-pyran-2-yl)-9H-purine-2,6-diamine(4.17 g) in chloroform (46.0 ml) at 0° C., was added N-bromosuccinimide(2.58 g) to give a dark green suspension. The reaction mixture wasstirred at room temperature for 1 h. The reaction mixture was taken upin dichloromethane (100 ml) and washed with water (1×100 ml). Theorganic layer was separated, dried by passing through a hydrophobic fritand concentrated in vacuo to give a green gum (5.50 g, 80% pure).

MS calcd for (C₁₅H₂₁BrN₆O)⁺=380, 382

MS found (electrospray): (M+H)⁺=381, 383

Intermediate 147:N²-(2-Cyclopropylethyl)-8-(methoxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purine-2,6-diamine

To a solution of8-bromo-N²-(2-cyclopropylethyl)-9-(tetrahydro-2H-pyran-2-yl)-9H-purine-2,6-diamine(5.50 g) in methanol (48.1 ml) at room temperature was added sodiummethoxide (9.9 ml, 25% wt in methanol) to give a brown solution. Thereaction mixture was stirred at reflux for 24 hours. The reaction wasallowed to cool before adding ammonium chloride solution (100 ml) andextracting with ethyl acetate (150 ml). The organic layer was separatedand washed with water (100 ml). The organic layer was separated, driedover magnesium sulfate, filtered and concentrated in vacuo to give abrown solid (3.79 g). The product was purified by C₁₈ reverse phasechromatography using water (containing 0.1% formic acid)-acetonitrile(containing 0.05% formic acid) as eluant (20-60%) to afford the titlecompound as an brown gum (3.3 g, 79% pure).

MS calcd for (C₁₆H₂₄N₆O₂)⁺=332

MS found (electrospray): (M+H)⁺=333

Intermediate 148:N²-(2-Cyclopropylethyl)-8-(methoxy)-9H-purine-2,6-diaminetrifluoroacetate

To a solution ofN²-(2-cyclopropylethyl)-8-(methoxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purine-2,6-diamine(3.30 g) in methanol (33.0 ml) at room temperature was addedtrifluoroacetic acid (3.30 ml) to give an orange solution. The reactionmixture was stirred at room temperature for 70 hours. The reactionmixture was concentrated in vacuo to give a yellow solid which was thentriturated in diethyl ether (100 ml) and filtered under vacuum to givean off-white solid (2.4 g).

MS calcd for (C₁₁H₁₆N₆O)⁺=248

MS found (electrospray): (M+H)⁺=249

Intermediate 149:N²-(2-Cyclopropylethyl)-8-(methoxy)-9-(tetrahydro-3-furanylmethyl)-9H-purine-2,6-diamine

To a solution ofN²-(2-cyclopropylethyl)-8-(methoxy)-9H-purine-2,6-diaminetrifluoroacetate (400 mg) in N,N-dimethylformamide (6.90 ml) at roomtemperature was added potassium carbonate (610 mg) and the reactionmixture stirred at 60° C. for 90 minutes. The reaction was cooled toroom temperature and tetrahydro-3-furanylmethyl methanesulfonate (219mg) was added, stirring was continued at 50° C. for 20 h. The reactiontemperature was increased to 90° C. and stirring continued. The reactionwas cooled and taken up in ethyl acetate (50 ml) and washed with water(2×50 mL). The organic layer was separated, dried over magnesiumsulfate, filtered and concentrated in vacuo to give an orange oil. Theproduct was purified by C₁₈ reverse phase chromatography using water(containing 0.1% formic acid)-acetonitrile (containing 0.05% formicacid) as eluant (10-45%) to afford the title compound as a yellow oil(209 mg, 84% pure).

MS calcd for (C₁₆H₂₄N₆O₂)⁺=332

MS found (electrospray): (M+H)⁺=333

Intermediate 150:N²-(2-Cyclopropylethyl)-8-(methyloxy)-9-(tetrahydro-2H-pyran-3-ylmethyl)-9H-purine-2,6-diamine

To a solution ofN²-(2-cyclopropylethyl)-8-(methoxy)-9H-purine-2,6-diaminetrifluoroacetate (400 mg) in N,N-dimethylformamide (6.90 ml) at roomtemperature was added potassium carbonate (610 mg) and the reactionstirred at 60° C. for 90 minutes. The reaction mixture was cooled toroom temperature and tetrahydro-2H-pyran-3-ylmethyl methanesulfonate(236 mg) was added. Stirring was continued at 50° C. for 20 hours. Thereaction temperature was increased to 90° C. and stirring continued. Thereaction was cooled and taken up in ethyl acetate (50 ml) and washedwith water (2×50 ml). The organic layer was separated, dried overmagnesium sulfate, filtered and concentrated in vacuo to give an orangeoil. The product was purified by C₁₈ reverse phase chromatography usingwater (containing 0.1% formic acid)-acetonitrile (containing 0.05%formic acid) as eluant (10-50%) to afford the title compound as acolourless oil (198 mg, 88% pure).

MS calcd for (C₁₇H₂₆N₆O₂)⁺=346

MS found (electrospray): (M+H)⁺=347

Intermediate 151:8-Bromo-2-({2-[(1-methylethyl)oxy]ethyl}oxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

2-Chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (5 g, 20 mmol)was added to a stirring solution of potassium tert.-butoxide in2-[(1-methylethyl)oxy]ethanol (50 ml). The mixture was heated to 80-90°C. for 4 h. The alcohol was removed under reduced pressure. The residuewas added to ethyl acetate and was washed with water three times, dried,filtered and concentrated to give the crude product. This product wassemipurified by silica gel chromatography eluting with 1:1 ethylacetate:petroleum ether to give material (3.3 g). This and similarlyprepared material were used in the next stage. To this material (6.8 g,21.2 mmol) in DCM was added NBS (4.15 g, 23.3 mmol). Stirred for 16 h atroom temperature and washed twice with aqueous sodium bicarbonate. Thecrude product was purified through silica gel eluting with 1:2 ethylacetate:petroleum ether to give the title compound (5.6 g).

¹H NMR (CDCl₃): 6.15-5.95 (2H, br. s), 5.52 (1H, m), 4.38 (2H, m),4.15-4.0 (1H, m), 3.73 (2H, t), 3.7-3.55 (2H, m), 3.05-2.85 (1H, m),2.1-1.95 (1H, m), 1.85-1.45 (4H, overlapping m), 1.12 (6H, d).

Intermediate 152:2-({2-[(1-Methylethyl)oxy]ethyl}oxy)-8-(methoxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To methanol (120 ml) was added sodium (0.966 g). When the metal wasdissolved,8-bromo-2-({2-[(1-methylethyl)oxy]ethyl}oxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(5.69 g, 21.2 mmol) was added, heated to reflux and the solution stirredfor 16 h, cooled to room temperature. The solvent was removed. Extractedwith ethyl acetate after adding water, dried and concentrated to givethe crude product which was purified through silica gel eluting with 2:1ethyl acetate:petroleum ether to give the title compound (4.8 g).

¹H NMR (CDCl₃): 5.47 (1H, m), 5.33 (2H, br. s), 4.41 (2H, m), 4.2-4.0(4H, br. s), 3.76 (2H, m), 3.7-3.55 (2H, m), 2.85-2.65 (1H, m), 2.1-1.9(1H, m), 1.85-1.45 (4H, overlapping m), 1.17 (6H, d).

Intermediate 153:2-({2-[(1-Methylethyl)oxy]ethyl}oxy)-8-(methoxy)-9H-purin-6-aminetrifluoroacetate

To2-({2-[(1-methylethyl)oxy]ethyl}oxy)-8-(methoxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(4.5 g, 14 mmol) in methanol (30 ml) was added trifluoroacetic acid (8ml), stirred for 10 min and held at room temperature for 2 days.Filtered to give the crude product which was purified by preparativehplc (Gilson GX-281 instrument with YMC C18 5.0 um column (250×20 mm)eluting with water containing TFA (0.1%): acetonitrile 30-60%. This gavethe title compound 2.1 g.

¹H NMR (CDl₃OD): 4.55 (2H, m), 4.13 (3H, s), 3.78 (2H, t), 3.67 (1H, m),1.14 (6H, d). Exchangeable protons not observed.

Intermediate 154: Tetrahydro-3-furancarbonyl chloride

To tetrahydro-3-furancarboxylic acid (24.3 g) in anhydrousdichloromethane (299 ml) at room temperature and under nitrogen wasadded oxalyl chloride (27.5 ml) dropwise over 10 minutes followed by afew drops of DMF. The reaction was allowed to stir overnight. Thereaction was concentrated in vacuo to yield an orange oil (28 g).

¹H NMR (CDCl₃): δ 4.11 (1H, dd), 4.01 (1H, m), 3.93 (1H, m), 3.84 (1H,m), 3.57 (1H, m), 2.34 (1H, m), 2.23 (1H, m).

Intermediate 155 (diastereoisomer 1) and Intermediate 156(diastereoisomer 2):(4R)-4-(Phenylmethyl)-3-[(3S)-tetrahydro-3-furanylcarbonyl]-1,3-oxazolidin-2-oneand(4R)-4-(phenylmethyl)-3-[(3S)-tetrahydro-3-furanylcarbonyl]-1,3-oxazolidin-2-one

To a solution of (4R)-4-(phenylmethyl)-1,3-oxazolidin-2-one (31 g) inanhydrous tetrahydrofuran (583 ml) at −78° C. and under nitrogen, wasadded n-butyllithium (115 ml) dropwise over 30 minutes maintaining theinternal temperature below −65° C. The reaction was stirred at −78° C.for 25 minutes and then a solution of tetrahydro-3-furancarbonylchloride (28.2 g) in anhydrous tetrahydrofuran (20 ml) was addeddropwise over 20 minutes maintaining the temperature below −65° C.Following the addition the reaction was warmed over 30 minutes to roomtemperature. The reaction was quenched with saturated aqueous ammoniumchloride (50 ml) and then concentrated in vacuo. The residue was takenup in dichloromethane (400 ml) and washed with brine (2×50 ml). Theorganic layer was dried through a hydrophobic frit and concentrated invacuo. The product was purified by silica chromatography (1.5 kg) (ISCO)using a gradient elution of 2% ethyl acetate:dichloromethane. Thisyielded 15 g of the faster moving product (semi-pure Diastereoisomer 1)and 15 g of the slower moving product (semi-pure Diastereoisomer 2).About 20 g of mixed fractions were also collected.

Semi-pure diastereoisomer 1 was crystallised from cyclohexane/5% ethylacetate. The crystals were collected by suction filtration and dried ona rotary evaporator at 50° C. for 15 minutes. ¹HNMR indicated presenceof the other diastreoisomer. The product was further purified by silicachromatography (˜800 g, Toluene/5% Diethyl ether) to afforddiastereoisomer 1 as a white solid (6.85 g, 98.4:1.56 by chiral HPLC).Semi-pure diastereoisomer 2 was recrystallised from cyclohexane/5% ethylacetate. The crystals were collected by suction filtration and dried ona rotary evaporator at 50° C. for 15 minutes. ¹HNMR indicated presenceof the other diastreoisomer. The product was purified by silicachromatography (˜800 g, Toluene/5% Diethyl ether) to afford a whitesolid (96:4 by chiral HPLC). This was recrystallised fromcyclohexane/15% ethyl acetate to afford diastereoisomer 2 as whitecrystals (6.2 g, 96.4:3.6 by chiral HPLC).

The mixed fractions (˜20 g) were purified by silica chromatography ISCO(1.5 kg) (ISCO) using a gradient elution of 5% TBME/Toluene to affordsemi-pure diastereoisomer 1, as a clear oil that crystallises (7.3 g,95.2:4.80 by chiral HPLC) and semi-pure diastereoisomer 2 as a clear oilthat crystallises (6.7 g, 96.1:3.80 by chiral HPLC).

The two solid batches of diastereoisomer 1 were combined andrecrystallised from cyclohexane:ethyl acetate, 5:1. The crystals werefiltered. This recrystallisation process was repeated 3 times to afforddiastereoisomer 1 (10.7 g, 98.5:1.5 by chiral HPLC).

The two solid batches of diastereoisomer 2 were combined. The combinedsolids were recrystallised from Cyclohexane:ethyl acetate, 5:1. Thecrystals were filtered. This recrystallisation process was repeated 3times to afford diastereoisomer 2 (9.6 g, 99.5:0.5 by chiral HPLC).

Intermediate 155 (diastereoisomer 1)¹H NMR (CDCl₃): δ 7.43-7.31 (3H, m),7.29-7.23 (2H, m), 4.75 (1H, m), 4.33-4.25 (2H, m), 4.23-4.12 (2H, m),4.07-4.00 (2H, m), 3.90 (1H, m), 3.33 (1H, dd), 2.86 (1H, dd), 2.39 (1H,m), 2.19 (1H, m).

Intermediate 156 (diastereoisomer 2)¹H NMR (CDCl₃): δ 7.43-7.31 (3H, m),7.29-7.23 (2H, m), 4.74 (1H, m), 4.32-4.19 (3H, m), 4.10-4.03 (2H, m),4.00 (1H, m), 3.90 (1H, m), 3.36 (1H, dd), 2.84 (1H, dd), 2.31 (2H, m).

Intermediate 155 and Intermediate 156, alternative procedure:(4R)-4-(Phenylmethyl)-3-[(3S)-tetrahydro-3-furanylcarbonyl]-1,3-oxazolidin-2-oneand(4R)-4-(phenylmethyl)-3-[(3R)-tetrahydro-3-furanylcarbonyl]-1,3-oxazolidin-2-one

To tetrahydro-3-furoic acid (13 g) in dry toluene (90 ml) at roomtemperature and under nitrogen, was added(4R)-4-(phenylmethyl)-1,3-oxazolidin-2-one (10 g) in one go followed bydry triethylamine (31.5 ml) in one go. The reaction was heated to 80° C.and to the clear solution was added pivaloyl chloride (13.9 ml) dropwiseover five minutes after which the reaction turns cloudy and viscous. Thereaction was heated to 115° C. overnight. The reaction was cooled toroom temperature and diluted with ethyl acetate (150 ml). This mixturewas washed with 2M HCl (50 ml), water (50 ml) and a saturated aqueoussolution of sodium hydrogen carbonate (50 ml). The organic layer wasdried over magnesium sulfate, filtered and concentrated in vacuo toyield a brown viscous oil. The product was purified by silicachromatography (˜750 g) using a gradient elution of toluene/10% diethylether to afford 4.6 g of the faster moving product (Diastereoisomer 1,99.5:0.5 by chiral HPLC) and 4.3 g of the slower moving product(Diastereoisomer 2, 91.8:8.2 by chiral HPLC).

¹H NMR (CDCl₃): As for first procedure.

Intermediate 157: Tetrahydro-3-furanylmethanol (Isomer 1)

To a solution of(4R)-4-(phenylmethyl)-3-[tetrahydro-3-furanylcarbonyl]-1,3-oxazolidin-2-one,Diastereomer 1 (4.6 g) in diethyl ether (320 ml, AR grade) and water(0.33 ml), at 0° C., was added lithium borohydride (9.2 ml, 2M solutionin tetrahydrofuran) dropwise over 5 minutes, maintaining the temperaturebetween 0-5° C. The reaction was left to stir for 30 minutes at thistemperature and then warmed to room temperature for 3 hours. A whiteprecipitate forms during the reaction. 2M sodium hydroxide (8.4 ml) wasthen added dropwise. The reaction turns clear and is stirred for 20minutes at room temperature. The organic layer was decanted, dried overMgSO₄, filtered through celite and concentrated in vacuo. The productwas purified by silica chromatography (120 g) (ISCO) using a gradientelution of cyclohexane:ethyl acetate, 0-70%, to afford the titlecompound as a clear oil (1.3 g).

¹H NMR (CDCl₃): δ 3.90-3.81 (2H, m), 3.74 (1H, m), 3.67-3.55 (3H, m),2.47 (1H, m), 2.03 (1H, m), 1.64 (1H, m). Exchangeable protons notobserved.

Intermediate 157, alternative procedure: Tetrahydro-3-furanylmethanol(Isomer 1)

2-{[(Tetrahydro-3-furanylmethyl)oxy]carbonyl}benzoic acid (isomer 2,3.65 gm) was dissolved in THF (25 ml) and 4N sodium hydroxide (10.94 ml)added. The mixture was refluxed with vigorous stirring for 2 h, thenallowed to cool. After 16 h a few ml of brine was added and the mixtureextracted 3 times with ethyl acetate, and the combined extracts washedwith brine, dried by passing through a hydrophobic frit and evaporatedat >10 mbar pressure, water bath 40° C. to give the title compound as amilky oil, yield 1.3 gm.

¹H NMR (CDCl₃): δ 3.91-3.81 (2H, m), 3.79-3.71 (1H, m), 3.68-3.55 (3H,m), 2.53-2.42 (1H, m), 2.09-1.99 (1H, m), 1.68-1.60 (1H, m).Exchangeable protons not observed.

Intermediate 158: Tetrahydro-3-furanylmethanol (Isomer 2)

To a solution of(4R)-4-(phenylmethyl)-3-[tetrahydro-3-furanylcarbonyl]-1,3-oxazolidin-2-one,Diastereomer 2 (4.3 g) in diethyl ether (310 ml, AR grade) and water(0.31 ml), at 0° C., was added lithium borohydride (8.6 ml, 2M solutionin tetrahydrofuran) dropwise over 5 minutes, maintaining the temperaturebetween 0-5° C. The reaction was left to stir for 30 minutes at thistemperature and then warmed to room temperature for 3 hours. 2M sodiumhydroxide (7.6 ml) was then added over 5 minutes and the reaction wasstirred for 20 minutes at room temperature. The organic layer wasdecanted, dried over MgSO₄, filtered and concentrated in vacuo. Theproduct was purified by silica chromatography (120 g) (ISCO) using agradient elution of cyclohexane:ethyl acetate, 0-100%, to afford thetitle compound as a clear oil (1.4 g).

¹H NMR (CDCl₃): δ 3.90-3.81 (2H, m), 3.74 (1H, m), 3.67-3.55 (3H, m),2.47 (1H, m), 2.03 (1H, m), 1.64 (1H, m). Exchangeable protons notobserved.

Intermediate 158, alternative procedure: Tetrahydro-3-furanylmethanol(Isomer 2)

2-{[(Tetrahydro-3-furanylmethyl)oxy]carbonyl}benzoic acid (isomer 1,4.89 gm) was dissolved in THF (30 ml) and 4N sodium hydroxide (14.7 ml)added. The mixture was refluxed with vigorous stirring for 2 h, thenallowed to cool. After 16 h a few ml of brine was added and the mixtureextracted 3 times with DCM. The combined extracts were dried by passingthrough a hydrophobic frit and evaporated at >10 mbar pressure, waterbath 40° C. to give the title compound as a pinkish oil, yield 1.77 gm.

¹H NMR (CDCl₃): δ 3.89-3.82 (2H, m), 3.77-3.71 (1H, m), 3.67-3.56 (3H,m), 2.52-2.42 (1H, m), 2.07-1.99 (1H, m), 1.68-1.61 (1H, m).Exchangeable protons not observed.

Intermediate 159: Tetrahydro-3-furanylmethyl methanesulfonate (Isomer 1)

To tetrahydro-3-furanylmethanol, Isomer 1 (1.3 g) in dry dichloromethane(40 ml) at 0° C. and under nitrogen, was added triethylamine (4.09 ml)followed by methanesulfonyl chloride (1.29 ml). The reaction was stirredat room temperature overnight. The orange solution was diluted withdichloromethane (80 ml) and washed with saturated aqueous sodiumbicarbonate (40 ml). The organic layer was separated, dried through ahydrophobic frit and concentrated in vacuo to yield the title compoundas a yellow oil (2.2 g).

¹H NMR ((CD₃)₂SO): δ 4.13 (2H, m), 3.77-3.68 (1H, m), 3.62 (1H, m), 3.46(1H, m), 3.19 (3H, s), 2.58 (1H, m), 1.97 (1H, m), 1.57 (1H, m).

Intermediate 160: Tetrahydro-3-furanylmethyl methanesulfonate (Isomer 2)

To (3S)-tetrahydro-3-furanylmethanol, Isomer 2 (1.4 g) in drydichloromethane (40 ml) at 0° C. and under nitrogen, was addedtriethylamine (3.83 ml) followed by methanesulfonyl chloride (1.39 ml).The reaction was stirred at room temperature overnight. The orangesolution was diluted with dichloromethane (50 ml) and washed withsaturated aqueous sodium bicarbonate (20 ml). The organic layer wasseparated, dried through a hydrophobic frit and concentrated in vacuo toyield the title compound as an orange oil (2.6 g).

¹H NMR ((CD₃)₂SO): δ 4.13 (2H, m), 3.77-3.68 (1H, m), 3.62 (1H, m), 3.46(1H, m), 3.19 (3H, s), 2.58 (1H, m), 1.97 (1H, m), 1.57 (1H, m).

Intermediate 161:N²-Butyl-8-(methoxy)-9-[(tetrahydro-3-furanylmethyl]-9H-purine-2,6-diamine(Isomer 1)

To a solution of N²-butyl-8-methoxy-9H-purine-2,6-diaminetrifluoroacetic acid salt (3.89 g) in dry N,N-dimethylformamide (46 ml)at room temperature and under was added potassium carbonate (6.14 g) inone go. The reaction was heated to 60° C., under nitrogen, for 1.5hours. A solution of tetrahydro-3-furanylmethyl methanesulfonate, Isomer1 (2.2 g) in dry N,N-dimethylformamide (2 ml) was added via a Pasteurpipette and the reaction heated at 70° C. for 16 hours. The reaction wascooled to room temperature, diluted with ethyl acetate (100 ml) andwashed with brine (20 ml). The organic layer was concentrated in vacuo.The product was purified by C₁₈ reverse phase chromatography using water(0.1% formic acid)-acetonitrile (0.05% formic acid) as eluant (10-50%)to afford the title compound as a clear viscous oil (2.79 g).

MS calcd for (C₁₅H₂₄N₆O₂)⁺=320

MS found (electrospray): (M+H)⁺=321

Intermediate 162:N²-Butyl-8-(methoxy)-9-[(tetrahydro-3-furanylmethyl]-9H-purine-2,6-diamine(Isomer 2)

To a solution of N²-butyl-8-methoxy-9H-purine-2,6-diaminetrifluoroacetic acid salt (4.60 g) in dry N,N-dimethylformamide (55 ml)at room temperature and under was added potassium carbonate (7.25 g) inone go. The reaction was heated to 60° C. for 1.5 hours. A solution oftetrahydro-3-furanylmethyl methanesulfonate, Isomer 2 (2.6 g) in dryN,N-dimethylformamide (3 ml) was added via a Pasteur pipette and thereaction heated at 70° C. for 16 hours. The reaction was cooled to roomtemperature, diluted with ethyl acetate (100 ml) and washed with brine(20 ml). The organic layer was concentrated in vacuo. The product waspurified by C₁₈ reverse phase chromatography using water (0.1% formicacid)-acetonitrile (0.05% formic acid) as eluant (10-60%) to afford thetitle compound as a clear viscous oil (3 g).

MS calcd for (C₁₅H₂₄N₆O₂)⁺=320

MS found (electrospray): (M+H)⁺=321

Intermediate 163: 2-{[(Tetrahydro-3-furanylmethyl)oxy]carbonyl}benzoicacid

A mixture of phthalic anhydride (7.41 gm) and tetrahydro-3-furanmethanolwere heated with stirring at 130° C. under nitrogen. After 1.5 h, theclear liquid was allowed to cool, treated with water and extracted withEtOAc (×3). The combined organics were dried by passing through ahydrophobic frit and evaporated to a clear oil which crystallised ontrituration with light petrol. The solid was filtered, washed and dried,yield 11.93 gm.

MS calcd for (C₁₃H₁₄O₅)⁺=250

MS found (electrospray): (M+H)⁺=251

Intermediate 164 and Intermediate 165:2-{[(Tetrahydro-3-furanylmethyl)oxy]carbonyl}benzoic acid, (Isomers 1and 2)

2-{[(Tetrahydro-3-furanylmethyl)oxy]carbonyl}benzoic acid (11.93 gm) wasseparated in 250 mg portions by chiral HPLC using a 5 cm×20 cm ChiralpakAD column, eluting with heptane:ethanol containing 0.1% trifluoroaceticacid (80:20). Mixed fractions were evaporated and separated again asdescribed above. Fractions containing pure earlier eluting material werecombined and evaporated to give a white solid, yield 4.89 gm, Isomer 1,Intermediate 164.

1H NMR (CDCl₃): 7.99 (1H, broad s), 7.93-7.86 (1H, m), 7.74-7.65 (1H,m), 7.65-7.53 (2H, overlapping m), 4.44-4.34 (1H, m), 4.29-4.18 (1H, m),4.00-3.88 (2H, m), 3.85-3.67 (2H, overlapping m), 2.81-2.66 (1H, m),2.17-2.05 (1H, m), 1.80-1.68 (1H, m).

Fractions containing slower running material were treated similarly togive a white solid, yield 3.65 gm, Isomer 2, Intermediate 165.

1H NMR (CDCl₃): 7.92-7.84 (1H, m), 7.74-7.66 (1H, m), 7.63-7.52 (2H,overlapping m), 7.38 (1H, broad s), 4.43-4.33 (1H, m), 4.27-4.17 (1H,m), 3.98-3.87 (2H, m), 3.83-3.65 (2H, m), 2.79-2.65 (1H, m), 2.16-2.03(1H, m), 1.78-1.65 (1H, m).

Intermediate 166:2-[(2-Cyclopropylethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To a stirring solution of sodium tert.-butoxide (13.45 g) in DME (80 ml)was added dropwise under nitrogen a solution of 2-cyclopropylethanol(12.1 g) in DME (40 ml) over 5 min. After 30 min2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (11.84 g) wasadded and the stirring mixture refluxed for 20 h. After cooling themixture was treated with water and extracted twice with ethyl acetate.The combined extracts were washed with water then brine, dried bypassing through a hydrophobic frit and evaporated to a brown oil. Thiswas re-evaporated twice from toluene then purified on a silica columnusing an ISCO Companion, eluting with methanol:ethyl acetate (0-12%) togive the title compound. Yield 6.53 gm.

MS calcd for (C₁₅H₂₁N₅O₂)⁺=303

MS found (electrospray): (M+H)⁺=304

Intermediate 167:8-Bromo-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

To an ice cooled stirring solution of2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(6.53 g) in chloroform (75 ml), was added N-bromosuccinimide (4.02 g).The reaction mixture was allowed to warm to room temperature and after16 h treated with water and extracted twice with DCM. The combinedextracts were washed with dilute sodium metabisulphite then dilutebrine, dried by passing through a hydrophobic frit and evaporated togive the title compound as an orange foam, yield 7.96 gm.

MS calcd for (C₁₅H₂₀BrN₅O₂)⁺=381, 383

MS found (electrospray): (M+H)⁺=382, 384

Intermediate 168:2-[(2-Cyclopropylethyl)oxy]-8-(methoxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

A stirring suspension of8-bromo-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(7.96 g) in methanol (80 ml) was treated with 25 wt % sodium methoxidein methanol (14.29 ml) and refluxed under nitrogen for 3.5 h. Afterallowing to cool over 16 h the solvent was evaporated and the residuetreated with saturated ammonium chloride and extracted twice with ethylacetate. The combined extracts were washed with brine, dried by passingthrough a hydrophobic frit and evaporated to give the title compound asa brown solid, yield 6.49 gm.

MS calcd for (C₁₆H₂₃N₅O₃)⁺=333

MS found (electrospray): (M+H)⁺=334

Intermediate 169:2-[(2-Cyclopropylethyl)oxy]-8-(methoxy)-1H-purin-6-aminetrifluoroacetate salt

2-[(2-Cyclopropylethyl)oxy]-8-(methoxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(6.49 g) was treated with methanol (65 ml) and the resulting suspensionstirred and ice cooled whilst TFA (6.5 ml) was added. The mixture wasallowed to warm to room temperature and after 72 h the solvents wereevaporated and the remaining orange solid triturated with cold ethylacetate (50 ml), filtered, washed and dried under vacuum, to give thetitle compound yield 4.78 gm.

MS calcd for (C₁₁H₁₅N₅O₂)⁺=249

MS found (electrospray): (M+H)⁺=250

A second crop was obtained by evaporation of the filtrate andtrituration of the residue with ether, yield 0.99 gm. Slightly less purethan first crop.

Intermediate 170:2-[(2-Cyclopropylethyl)oxy]-8-(methoxy)-9-(tetrahydro-3-furanylmethyl)-9H-purin-6-amine(Isomer 1)

A stirring mixture of2-[(2-cyclopropylethyl)oxy]-8-(methoxy)-1H-purin-6-amine trifluoroaceticacid salt (2.89 g), potassium carbonate (4.41 g) and dry DMF (32 ml) washeated at 60° C. under nitrogen for 90 minutes.Tetrahydro-3-furanylmethyl methanesulfonate (1.869 g, isomer 1) was thenadded and stirring continued at 70° C. for 1 h, then at 90° C. for 2 h.The solvent was evaporated and the residue treated with water andextracted three times with ethyl acetate. The combined extracts werewashed with water then brine, dried by passing through a hydrophobicfrit and evaporated to a brown oil. This was purified on a 360 gm C18column using water (+0.1% formic acid)/acetonitrile (+0.05% formicacid). Appropriate fractions were combined and evaporated, yield 814 mg.

MS calcd for (C₁₆H₂₃N₅O₃)⁺=333

MS found (electrospray): (M+H)⁺=334

Intermediate 171:2-[(2-Cyclopropylethyl)oxy]-8-(methoxy)-9-[(tetrahydro-3-furanylmethyl]-9H-purin-6-amine(Isomer 2)

To a solution of2-[(2-cyclopropylethyl)oxy]-8-(methoxy)-1H-purin-6-amine trifluoroaceticacid salt (2.89 g) in dry N,N-dimethylformamide (32 ml) under nitrogenand at room temperature, was added potassium carbonate (4.41 g) in onego. The reaction was heated to 60° C. and stirred for 90 minutes. Asolution of tetrahydro-3-furanylmethyl methanesulfonate, Isomer 2 (1.869g) in dry DMF (3 ml) was then added gradually via pipette. The reactionwas heated to 70° C. and left to stir overnight. Still 22% startingmaterial present by LCMS, therefore increased temperature to 90° C. andstirred for a further 3 hours at this temperature. The reaction wascooled and diluted with ethyl acetate (100 ml) and washed with water (50ml) and brine (50 ml). The organic layer was concentrated in vacuo toyield an orange oil. The product was purified by C₁₈ reverse phasechromatography using water (0.1% formic acid)-acetonitrile (0.05% formicacid) as eluant (10-60%) to afford the title compound as an orangeviscous oil (1.45 g).

MS calcd for (C₁₆H₂₃N₅O₃)⁺=333

MS found (electrospray): (M+H)⁺=334

Intermediate 172:N²-Butyl-8-(methoxy)-9-(tetrahydro-3-furanylmethyl)-9H-purine-2,6-diamine

N²-Butyl-8-(methoxy)-3H-purine-2,6-diamine trifluoroacetic acid salt(0.25 g) and anhydrous potassium carbonate (0.395 g) in anhydrous DMF (3mL) was heated for 1 hour at 60° C. (external) under nitrogen, beforebeing allowed to cool to room temperature. To the reaction mixture wasthen added 3-(bromomethyl)tetrahydrofuran (0.236 g) and the reactionmixture heated under nitrogen to 50° C. (external) for 18.5 hours. Thereaction mixture was then diluted with water (15 mL) and extracted withdiethyl ether (15 mL, 3 times). The organic layers were combined anddried over anhydrous sodium sulphate. The sodium sulphate was filteredoff and the filtrate evaporated under reduced pressure to give an oil.This oil was triturated with cyclohexane and a little diethyl ether togive a solid. The cyclohexane and diethyl ether was evaporated underreduced pressure to give a white solid. The solid (0.2606 g) wasdissolved in hot ethanol (2 mL). To this solution was then added water(8 mL) and the resultant suspension was heated to reflux (93° C.,external) giving a solution. The solution was then allowed to coolslowly (by not removing the flask from the reaction block and turningthe power off to the heating block). This gave a solid gum on coolingwhich when sonicated gave a white solid. This solid was isolated byfiltration under suction and then dried under vacuo at 50° C.,overnight. This gave the title compound (0.1043 g) as a white solid.

MS calcd for (C₁₅H₂₄N₆O₂)⁺=320

MS found (electrospray): (M+H)⁺=321

¹H NMR (CDCl₃): δ 4.94 (2H, br s), 4.64-4.55 (1H, m), 4.1 (3H, s),3.98-3.82 (3H, m), 3.81-3.72 (2H, m), 3.68-3.62 (1H, m), 3.37 (2H, q),2.89-2.76 (1H, m), 2.02-1.91 (1H, m), 1.79-1.68 (1H, m), 1.62-1.52 (2H,m), 1.48-1.36 (2H, m), 0.95 (3H, t).

Intermediate 172, alternative procedure:N²-Butyl-8-(methoxy)-9-(tetrahydro-3-furanylmethyl)-9H-purine-2,6-diamine

N²-Butyl-8-(methoxy)-3H-purine-2,6-diamine trifluoroacetic acid salt(0.25 g) and anhydrous potassium carbonate (0.395 g) in anhydrous DMF (3mL) was heated under nitrogen at 60° C. (external) for 1 hour. Afterallowing the reaction mixture to cool to ambient room temperature,tetrahydro-2-furanylmethyl methanesulfonate (0.257 g) was added and thereaction mixture was heated for at 70° C. (external) for 18.5 hoursunder nitrogen. The reaction mixture [N2420-15-D3] was diluted withwater (15 mL) and extracted with diethyl ether (15 mL, 3 times). Theorganic layers were combined and dried over anhydrous sodium sulphate.The sodium sulphate was filtered off and the filtrate evaporated underreduced pressure to give an oily gum. This material was then trituratedwith cyclohexane and diethyl ether with scratching until a pale yellowsolid was obtained. The cyclohexane and diethyl ether was removed byevaporation under reduced pressure to give a pale yellow solid (0.2123g). This was dissolved in hot ethanol (2 mL). To this solution was addedwater (8 mL) to give an oily suspension that was then heated to reflux(90° C., external) giving a solution. The resultant solution was allowedto cool slowly by not removing the flask from the heating block andturning off the power to the heating block. On cooling to ambienttemperature, the resultant gum was sonicated and scratched to give asolid. This solid was filtered off under suction and the resultantfilter cake was washed with water (2 mL). The resultant white solid wasthen air-dried under suction before being dried further under vacuo at50° C. to constant weight to give the title compound as a slightlyoff-white solid (0.109 g).

MS calcd for (C₁₅H₂₄N₆O₂)⁺=320

MS found (electrospray): (M+H)⁺=321

¹H NMR (CDCl₃): δ 4.93 (2H, br s), 4.64-4.53 (1H, m), 4.1 (3H, s),3.98-3.82 (3H, m), 3.81-3.71 (2H, m), 3.69-3.61 (1H, m), 3.37 (2H, q),2.89-2.76 (1H, m), 2.03-1.91 (1H, m), 1.79-1.68 (1H, m), 1.63-1.51 (2H,m), 1.48-1.36 (2H, m), 0.95 (3H, t).

Intermediate 173: 2-[(3S)-Tetrahydro-3-furanyl]ethanol

Boran-tetrahydrofuran-complex, 1M in THF (50 ml, 50.0 mmol) was addeddropwise over one hour to a stirred solution of(3R)-tetrahydro-3-furanylacetic acid (2.4 g, 18.44 mmol) (J. Med. Chem.,1993, 36, 2300) in dry THF (35 ml) cooled to −5° C. under a nitrogenatmosphere. The reaction mixture was warmed to room temperature and leftstirring under nitrogen atmosphere for 16 hours. The reaction mixturewas cooled down to −5° C. and methanol (15 ml) was added dropwise,keeping the temperature under 5° C. The solution was concentrated undervacuum and the residue was dissolved in DCM and purified bychromatography on silica (100 g) using a gradient ofdichloromethane:ethyl acetate (0-100% gradient over 40 mins). Thedesired fractions were combined and concentrated under vacuum to givetitle compound as a colourless oil (1.4 g).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.38-1.52 (m, 3H) 1.91-2.01 (m, 1H)2.11-2.24 (m, 1H) 3.17-3.23 (m, 1H) 3.35-3.46 (m, 2H) 3.56-3.63 (m, 1H)3.66-3.72 (m, 2H excess) 3.75-3.80 (m, 2H excess) OH not observed

Intermediate 174: (3R)-3-(2-Bromoethyl)tetrahydrofuran

A solution of triphenylphosphine (6.32 g, 24.11 mmol) in drydichloromethane (10 ml) was added dropwise over 30 minutes to a stirredsolution of 2-[(3S)-tetrahydro-3-furanyl]ethanol (1.4 g, 12.05 mmol) andcarbon tetrabromide (7.99 g, 24.11 mmol) in dry dichloromethane (20 ml)at −2° C. under a nitrogen atmosphere. The reaction mixture was warmedto room temperature and left stirring under nitrogen atmosphere for 20hours. The reaction mixture was filtered on celite and the white solidwas washed with ether and DCM. The orange filtrate was concentratedunder vacuum. The residue was dissolved in DCM and purified bychromatography on silica (100 g) using a gradient of cyclohexane:ethylacetate (0-25% gradient over 40 mins). The desired fractions werecombined and concentrated under vacuum to give the title compound as acolourless oil (1.4 g).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.43-1.54 (m, 1H) 1.84-1.91 (m, 2H)1.94-2.03 (m, 1H) 2.23-2.31 (m, 1H) 3.24-3.28 (m, 1H) 3.49-3.56 (m, 2H)3.58-3.65 (m, 1H) 3.68-3.74 (m, 1H) 3.75-3.80 (m, 1H)

[α]=−9.01 (c=1 in EtOAc, 20° C.)

Intermediate 175: 2-[(3R)-Tetrahydro-3-furanyl]ethanol

A solution of (3S)-tetrahydro-3-furanylacetic acid (1.8 g, 13.83 mmol)(J. Med. Chem., 1993, 36, 2300) in dry THF (35 ml) was stirred andcooled to −5° C. under nitrogen atmosphere. Lithium Aluminium hydride,1M in Ether (20.75 ml, 20.75 mmol) was added keeping the temperatureunder 0° C. The reaction mixture was then warmed to room temperature andleft stirring under nitrogen atmosphere for 3 hours. The reactionmixture was cooled down to −5° C. and more lithium aluminium hydride, 1Min ether (20.75 ml, 20.75 mmol) was added, keeping the temperature under0° C. The reaction mixture was again warmed to room temperature and leftstirring under a nitrogen atmosphere for 16 hours. The reaction mixturewas cooled down to −5° C. and quenched with saturated aqueous NH₄Clsolution (15 ml) which was added dropwise keeping the temperature under5° C. After, ether (100 ml) was added. The mixture was filtered and theobtained white solid was washed with ether (50 ml) and saturated aqueousNH₄Cl solution (50 ml). The phases of the filtrate were separated andthe organic layer was dried by passing through a hydrophobic frit andconcentrated under vacuum. The white solid was then washed withsaturated aqueous NH₄Cl solution (50 ml) and EtOAc (50 ml). The phasesof the filtrate were separated and the organic layer was dried andconcentrated under vacuum. The aqueous phases were combined andextracted with EtOAc (4×100 ml). All the organic extracts were combined,dried using a hydrophobic frit and concentrated under vacuum to give thetitle compound as a colourless oil (1 g).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.38-1.52 (m, 3H) 1.92-2.02 (m, 1H)2.11-2.24 (m, 1H) 3.17-3.23 (m, 1H) 3.34-3.47 (m, 2H) 3.55-3.64 (m, 1H)3.65-3.73 (m, 1H) 3.74-3.81 (m, 1H) 4.35-4.41 (m, 1H)

Intermediate 176: (3S)-3-(2-Bromoethyl)tetrahydrofuran

Prepared similarly to Intermediate 174 from2-[(3R)-tetrahydro-3-furanyl]ethanol

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.44-1.54 (m, 1H) 1.84-1.91 (m, 2H)1.94-2.03 (m, 1H) 2.21-2.33 (m, 1H) 3.24-3.28 (m, 1H) 3.50-3.57 (m, 2H)3.58-3.65 (m, 1H) 3.68-3.75 (m, 1H) 3.77 (dd, J=8.28, 7.28 Hz, 1H)

[α]=+9.01 (c=1 in EtOAc, 20° C.)

Intermediate 177: 3-(Tetrahydro-3-furanyl)propanoic acid

A solution of (2E)-3-(3-furanyl)-2-propenoic acid (4.75 g, 34.4 mmol)and 10% palladium on carbon (0.366 g, 3.44 mmol) in ethyl acetate (100ml) was hydrogenated at atmospheric pressure and room temperature for 72hours. Hydrogen uptake ˜1.4 L (expected 2.4 L). The catalyst wasfiltered through Celite and concentrated in vacuo to give a brown oil.Analysis by ¹H-NMR showed that the some material still contained thefuran ring. Hydrogenation was continued under the same conditions withfresh catalyst for a further 24 hours with additional hydrogen uptake of400 ml. The catalyst was filtered through Celite and the filtrateconcentrated in vacuo to afford the title compound as a colourless oil(4.73 g).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.37-1.48 (m, 1H) 1.50-1.63 (m, 2H)1.90-2.01 (m, 1H) 2.04-2.17 (m, 1H) 2.17-2.29 (m, 2H) 3.18-3.25 (m, 1H)3.56-3.65 (m, 1H) 3.67-3.79 (m, 2H) 12.00 (br. s., 1H)

Intermediate 178: 3-(Tetrahydro-3-furanyl)-1-propanol

To a solution of 3-(tetrahydro-3-furanyl)propanoic acid (1 g, 6.94 mmol)in dry THF (20 ml) at 0° C. was added a 1M solution of Boron THF complex(21.16 ml, 21.16 mmol) in THF dropwise over 2 mins. The mixture wasstirred at 0° C. for 1 hour then allowed to warm to room temperature andstirred for 18 h. The reaction mixture was cautiously quenched withmethanol (˜20 ml) and the solvent removed in vacuo. The residue wasre-dissolved in methanol and concentrated in vacuo four times to givethe title compound a colourless oil (3.37 g)

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.26-1.50 (m, 5H) 1.90-2.01 (m, 1H) 2.09(spt, J=7.28 Hz, 1H) 3.13-3.22 (m, 1H) 3.34-3.43 (m, 2H) 3.56-3.65 (m,1H) 3.66-3.74 (m, 1H) 3.74-3.81 (m, 1H) 4.33 (br. s, 1H)

Intermediate 179: 3-(3-Bromopropyl)tetrahydrofuran

3-(Tetrahydro-3-furanyl)-1-propanol (1 g, 7.68 mmol) was dissolved inDMF (10 ml) and carbon tetrabromide (5.09 g, 15.36 mmol) added. Thesolution turned yellow. The solution was cooled to 0° C. andtriphenylphosphine (4.03 g, 15.36 mmol) added dropwise as a solution inDMF (20 ml) (˜30 mins, temperature maintained <2° C. throughout). Thereaction mixture was stirred at 0° C. for 1 hour before graduallyallowing to warm to room temperature and stirred for a further 2 hours.The solvent was removed in vacuo. Attempted trituration of the resultantbrown oil with either DCM or cyclohexane was unsuccessful. The solventwas removed and the oil diluted with DCM and was purified bychromatography on silica (100 g) using a 0-25% ethyl acetate-cyclohexaneover 40 mins using a Flashmaster II. The appropriate fractions werecombined and dried down to give the title compound as a yellow oil(0.676 g).

¹H NMR (400 MHz, DMSO-d₆) δ ppm 1.37-1.49 (m, 5H, excess) 1.74-1.88 (m,2 H) 1.93-2.02 (m, J=12.20, 7.58, 7.58, 4.77 Hz, 1H) 2.13 (spt, J=7.36Hz, 1H) 3.18-3.24 (m, 1H) 3.50-3.56 (m, 1H) 3.57-3.65 (m, 1H) 3.67-3.74(m, 1H) 3.75-3.81 (m, 1H)

Intermediate 180: 3-{(1E/Z)-4-[(Phenylmethyl)oxy]-1-buten-1-yl}furan

To a suspension of (3-benzyloxypropyl)triphenylphosphonium bromide (25.6g, 52.0 mmol) in dry THF (60 ml) at −15° C. was added butyllithium (32.5ml, 1.6M in hexanes) dropwise to give a solution. A solution of3-furancarbaldehyde (5 g, 52.0 mmol) in THF (20 ml) was added dropwiseto form a dark orange/red solution. The reaction mixture was stirred at−10° C. for 30 mins before 3-furancarbaldehyde (5 g, 52.0 mmol) wasadded dropwise as a solution in tetrahydrofuran (20 ml) to give a brownsolution. The reaction mixture was then allowed to warm to roomtemperature and stirred overnight A pale brown precipitate had formed sothe reaction mixture was filtered through Celite and washed with diethylether. The filtrate was concentrated in vacuo to give a dark orange oilwhich was loaded in DCM and purified in two batches by chromatography onsilica (100 g) using a 0-25% gradient of ethyl acetate-cyclohexane over40 mins using a Flashmaster II. The appropriate fractions were combinedand evaporated in vacuo to give the title compound as a pale yellow oil(6.11 g).

LCMS (Method B): t_(RET)=1.31 min; MH⁺ 229

Intermediate 181: 4-(Tetrahydro-3-furanyl)-1-butanol

A solution of 3-{4-[(phenylmethyl)oxy]-1-buten-1-yl}furan (6.11 g, 26.8mmol) and 10% palladium on carbon (0.285 g, 2.68 mmol) in ethyl acetate(150 ml) and acetic acid (15 ml) was hydrogenated at atmosphericpressure and room temperature for 24 hours. The catalyst was filteredthrough Celite and the filtrate concentrated in vacuo. ¹H NMR showed noreduction had occurred, so the reaction mixture was hydrogenated underthe same conditions for a further 72 hours. The catalyst was filteredthrough Celite and the filtrate concentrated in vacuo, ¹H NMR showed thedouble bond had been reduced but the benzyl and furan ring were stillintact. The residue was hydrogenated under the same conditions for afurther 2 days. The catalyst was filtered through Celite and thefiltrate concentrated in vacuo.

A portion of the material (500 mg) was dissolved in ethyl acetate (5 ml)and hydrogenated using a Thales H-cube (settings: RT, 20 bar, 1 ml/minflow rate) using 10% palladium on carbon as the catalyst. The resultantsolution was concentrated, ¹H NMR showed no change.

All batches of the material were combined, loaded in dichloromethane andpurified on silica (100 g) using a 0-25% gradient of ethylacetate-cyclohexane over 40 mins using a Flashmaster II. The appropriatefractions were combined and evaporated in vacuo, a solution of theresidue (3.42 g, 14.9 mmol) and 10% palladium on carbon (684 mg) inethyl acetate (100 ml) was hydrogenated at atmospheric pressure and roomtemperature for 24 hours. The catalyst was filtered through Celite andthe filtrate concentrated in vacuo to give the title compound as ayellow oil (2.22 g).

1H NMR (400 MHz, DMSO-d₆) δ ppm 1.21-1.47 (m, 7H) 1.88-2.01 (m, 1H)2.01-2.15 (m, 1H) 3.13-3.22 (m, 1H) 3.33-3.42 (m, 2H) 3.60 (q, J=7.78Hz, 1H) 3.65-3.81 (m, 2H) 4.30-4.36 (m, 1H)

Intermediate 182: 3-(4-Bromobutyl)tetrahydrofuran

Prepared similarly to Intermediate 174 from4-(tetrahydro-3-furanyl)-1-butanol.

1H NMR (400 MHz, DMSO-d₆) δ ppm 1.30-1.46 (m, 8H) 1.76-1.85 (m, 2H)1.92-2.01 (m, 1H) 2.05-2.15 (m, 1H) 3.16-3.22 (m, 1H) 3.50-3.55 (m, 2H)3.57-3.64 (m, 1H) 3.67-3.74 (m, 1H) 3.74-3.80 (m, 1H)

Intermediate 183: 2-(2-Bromoethyl)tetrahydro-2H-pyran

A solution of triphenylphosphine (1.93 g, 7.37 mmol) in DCM (10 ml) wasadded dropwise to a solution of intermediate 72 (0.80 g, 6.15 mmol) andcarbon tetrabromide (2853 mg, 8.60 mmol) in DCM (40 ml) at 0° C. undernitrogen. The solution was stirred at 0° C. for 15 min, cyclohexane (30ml) was added and the mixture was evaporated gently to remove DCM. Theresulting cyclohexane solution was decanted from the gummy precipitatedirectly onto a silica cartridge (50 g) (pre-wetted with cyclohexane)and eluted with cyclohexane-DCM 1:1 to give the title compound as acolourless oil (0.68 g).

1H NMR (400 MHz, CDCl₃) ppm 1.23-1.35 (m, 1H) 1.48-1.62 (m, 4H)1.80-1.96 (m, 2H) 1.98-2.08 (m, 1H) 3.39-3.58 (m, 4H) 3.93-4.00 (m, 1H)

Intermediate 184: 2-(3-Bromopropyl)tetrahydro-2H-pyran

Prepared similarly to Intermediate 174 from3-(tetrahydro-2H-pyran-2-yl)-1-propanol (WO 2007/70201).

1H NMR (400 MHz, DMSO-d₆) δ ppm 1.08-1.21 (m, 1H) 1.36-1.57 (m, 8Hexcess) 1.70-1.95 (m, 3H) 3.17-3.32 (m, 2H) 3.43-3.57 (m, 2H) 3.49-3.56(m, 2H) 3.80-3.87 (m, 1H)

Intermediate 185: 2-(4-Bromobutyl)tetrahydro-2H-pyran

Prepared similarly to Intermediate 174 from4-(tetrahydro-2H-pyran-2-yl)-1-butanol (J. Am. Chem. Soc, 2005, 127,12180).

1H NMR (400 MHz, CDCl₃) δ ppm 1.20-1.32 (m, 1H) 1.37-1.64 (m, 11Hexcess) 1.78-1.93 (m, 2H) 3.20-3.28 (m, 1H) 3.38-3.46 (m, 3H) 3.94-4.00(m, 1H)

Intermediate 186: 2-(Tetrahydro-2H-pyran-3-yl)ethanol

A solution of lithium aluminium hydride in Et₂O (4.16 ml, 4.16 mmol) wasadded dropwise to a solution of tetrahydro-2H-pyran-3-ylacetic acid(Tet. Lett. 2003, 44, 6355) (0.6 g, 4.16 mmol) in THF (5 ml) at roomtemperature under nitrogen. The mixture was stirred for 1 hour and wastreated very slowly dropwise with water (1 ml). After the reaction wasquenched, aqueous sodium hydroxide (2N, 1 ml) was added and the mixturewas stirred for 5 min. The suspension was filtered through Hyflo andevaporated to the title compound as a colourless oil (0.3 g).

1H NMR (400 MHz, CDCl₃) δ ppm 1.12-1.94 (m, 9H excess) 3.06-3.15 (m, 1H)3.33-3.42 (m, 1H) 3.63-3.72 (m, 2H) 3.83-3.91 (m, 2H)

Intermediate 187: 3-(2-Bromoethyl)tetrahydro-2H-pyran

A solution of triphenylphosphine (725 mg, 2.77 mmol) in DCM (4 ml) wasadded dropwise with water-bath cooling to a solution of2-(tetrahydro-2H-pyran-3-yl)ethanol (300 mg, 2.304 mmol) and carbontetrabromide (917 mg, 2.77 mmol) in DCM (6 ml). The solution was stirredat room temperature for 2 hour and was evaporated onto florisil andapplied to a silica cartridge (20 g) pre-wetted with cyclohexane.Elution with cyclohexane-DCM (3:1) gave the title compound as acolourless oil (0.42 g).

1H NMR (400 MHz, CDCl₃) δ ppm 1.13-1.26 (m, 1H) 1.59-1.94 (m, 6H)3.08-3.16 (m, 1H) 3.35-3.48 (m, 3H) 3.82-3.91 (m, 2H)

Intermediate 188: 3-(3-Bromopropyl)tetrahydro-2H-pyran

Prepared similarly to Intermediate 174 from3-(tetrahydro-2H-pyran-3-yl)-1-propanol.

1H NMR (400 MHz, CDCl₃) δ ppm 1.09-1.40 (m, 5H excess) 1.56-1.67 (m, 3Hexcess) 1.81-1.92 (m, 4H) 3.02-3.11 (m, 1H) 3.32-3.45 (m, 3H) 3.82-3.92(m, 2H)

Intermediate 189: 3-(4-Bromobutyl)tetrahydro-2H-pyran

Prepared similarly to Intermediate 174 from4-(tetrahydro-2H-pyran-3-yl)-1-butanol.

1H NMR (400 MHz, CDCl₃) δ ppm 1.05-1.30 (m, 3H) 1.36-1.65 (m, 8H excess)1.79-1.92 (m, 3H) 2.99-3.10 (m, 1H) 3.30-3.46 (m, 3H) 3.81-3.92 (m, 2H)

Intermediate 190: 4-(3-Bromopropyl)tetrahydro-2H-pyran

Prepared similarly to Intermediate 174 from3-(tetrahydro-2H-pyran-4-yl)-1-propanol.

1H NMR (400 MHz, DMSO-d₆) δ ppm 1.04-1.19 (m, 2H) 1.25-1.36 (m, 2H)1.41-1.60 (m, 3H) 1.75-1.86 (m, 2H) 3.20-3.34 (m, 2H) 3.47-3.56 (m, 2H)3.76-3.85 (m, 2H)

Intermediate 191:4-{(1E/Z)-4-[(Phenylmethyl)oxy]-1-buten-1-yl}tetrahydro-2H-pyran

To a suspension of (3-benzyloxy-propyl)triphenyl-phosphonium bromide(21.57 g, 43.8 mmol) in dry THF (67 ml) at −15° C. was added 1.6M BuLiin Hexanes (27.4 ml, 43.8 mmol) dropwise for an hour to give a darkorange solution. The reaction was increased to 0° C. and stirring wascontinued for 30 minutes. A solution oftetrahydro-2H-pyran-4-carbaldehyde (5 g, 43.8 mmol) in dry THF (7 ml)was added dropwise at 0° C. for 15 minutes. The reaction mixture wasstirred at room temperature for 20 hours. This was filtered through prepacked celite (10 g) and washed with diethyl ether. The filtrate wasconcentrated in vacuo to give orange oil.

The crude material split into two batches and each pre-absorbed onsilica and purified by chromatography on silica (50 g) using a gradientof 0-25% ethyl acetate-cyclohexane over 60 mins using the FlashmasterII. The appropriate fractions were combined and evaporated in vacuo togive the title compound as a colourless oil (4.5059 g).

1H NMR (400 MHz, DMSO-d₆) δ ppm 1.22-1.35 (m, 2H) 1.40 (s, 5H excess)2.29-2.36 (m, 1H) 3.27-3.37 (m, 2H) 3.39-3.46 (m, 2H) 3.74-3.84 (m, 2H)4.46 (s, 2 H) 5.21-5.46 (m, 2H) 7.22-7.42 (m, 5H)

Intermediate 192: 4-(Tetrahydro-2H-pyran-4-yl)-1-butanol

A solution of4-{(1E)-4-[(phenylmethyl)oxy]-1-buten-1-yl}tetrahydro-2H-pyran (4.5059g, 18.29 mmol) and palladium on carbon (0.195 g, 0.183 mmol) in ethylacetate (140 ml) was hydrogenated at atmospheric pressure and roomtemperature. This was left to stir overnight in hydrogen. The mixturewas then filtered through pre-packed celite (10 g) to remove thepalladium and washed with ether (˜30 ml). The organic layer wasconcentrated in vacuo, ¹H NMR was carried out on the resulting oil toshow that benzyl group and double bonds were still present.

A solution of the material and palladium on carbon (0.3 g) in ethylacetate (140 ml) was hydrogenated at atmospheric pressure and roomtemperature. This was left to stir overnight in atmosphere of hydrogen.

The mixture was then put through pre-packed celite (10 g) to remove thepalladium and washed with ether (˜30 ml). The organic filtrate wasconcentrated in vacuo to give the title compound as a colourless oil(2.27 g)

1H NMR (400 MHz, DMSO-d₆) δ ppm 0.80-0.92 (m, 1H) 1.01-1.60 (m, 10H)3.17-3.42 (m, 4H) 3.74-3.87 (m, 2H) 4.32 (s, 0.6H)

Intermediate 193: 4-(4-Bromobutyl)tetrahydro-2H-pyran

Prepared similarly to Intermediate 174 from4-(tetrahydro-2H-pyran-4-yl)-1-butanol.

1H NMR (400 MHz, DMSO-d₆) δ ppm 1.04-1.27 (m, 4H) 1.33-1.60 (m, 5H)1.72-1.84 (m, 2H) 3.20-3.33 (m, 2H) 3.49-3.57 (m, 2H) 3.77-3.86 (m, 2H)

Intermediate 194:2,2-Dimethyl-4-[(E)-2-(methyloxy)ethenyl]tetrahydro-2H-pyran

To a stirred suspension of [(methyloxy)methyl](triphenyl)phosphoniumchloride (24.1 g, 70.3 mmol) in dry THF (70 ml) at −40° C. undernitrogen was added potassium t-butoxide, 1M soln in THF, (70 ml, 70.0mmol) dropwise over 30 mins. After stirring for 40 mins, the mixture wascooled to −70° C. and added a solution of2,2-dimethyltetrahydro-2H-pyran-4-carbaldehyde (2.5 g, 17.58 mmol) indry THF (10 ml) dropwise over 10 mins. The mixture was stirred at thistemp for 10 mins and the cooling bath was removed. The mixture wasstirred for a further 30 mins at ambient then quenched by pouring ontoice. The aqueous phase was extracted with Et₂O (3×100 ml), combined theorganic extracts and washed with saturated NaCl solution (100 ml), dried(Na₂SO₄) filtered and evaporated to dryness to give an amber oil (19 g).2 g of the crude product was loaded diethyl ether and purified on silica50 g using a 0-25% ethyl acetate-cyclohexane over 40 mins usingFlashmaster II. The fractions were monitored by staining in an Iodinetank and the appropriate fractions were combined and evaporated in vacuoto give the required product as a colourless oil.

The bulk of the crude mixture was then purified in the same way:cyclohexane followed by ether was added to the residue the mixture wasfiltered and the filtrate purified on silica 2×100 g using a gradient of0-25% ethyl acetate-cyclohexane over 40 mins on a Flashmaster II. Theappropriate fractions were identified by iodine staining and combinedand evaporated in vacuo. This was combined with the product obtainedfrom the first small scale purification to give the title compound as acolourless liquid (2.96 g).

1H NMR (400 MHz, CDCl₃) δ ppm 1.17-1.25 (m, 8H excess) 1.25-1.39 (m, 2H)1.48-1.59 (m, 2H) 2.22-2.34 (m, 0.6H) 2.76-2.88 (m, 0.3H) 3.50 (s, 2H)3.58 (s, 1H) 3.62-3.77 (m, 2H) 4.14 (dd, J=8.53, 6.27 Hz, 0.3H) 4.61(dd, J=12.67, 7.65 Hz, 0.6H) 5.82 (dd, J=6.27, 1.00 Hz, 0.3H) 6.32 (d,J=12.80 Hz, 0.6H)

Intermediate 195: (2,2-Dimethyltetrahydro-2H-pyran-4-yl)acetaldehyde

To a stirred solution of2,2-dimethyl-4-[(E)-2-(methyloxy)ethenyl]tetrahydro-2H-pyran (2.93 g,17.21 mmol) in THF (15 ml) was added 2N HCl (15 ml, 30.0 mmol) and themixture was stirred at 20° C. After 1 hour the mixture was extractedwith diethyl ether (3×25 ml); the combined ether extracts dried(Na₂SO₄), filtered and evaporated in vacuo (at 50 mbar and water bath at15° C.) to give the title compound as a pale yellow oil (2.56 g).

1H NMR (400 MHz, CDCl₃) δ ppm 1.19-1.29 (m, 9H excess) 1.53-1.65 (m, 4H)1.83-1.88 (m, 1H) 2.25-2.38 (m, 2H) 3.65-3.77 (m, 2H) 9.77-9.79 (m, 1H)

Intermediate 196: 2-(2,2-Dimethyltetrahydro-2H-pyran-4-yl)ethanol

A stirred suspension of sodium borohydride (0.620 g, 16.39 mmol) in dryethanol (20 ml) was cooled to 0° C. (ice bath) under nitrogen and asolution of (2,2-dimethyltetrahydro-2H-pyran-4-yl)acetaldehyde (2.56 g,16.39 mmol) in ethanol (20 ml) was added dropwise over a period of 20mins. The mixture was then stirred in the cold for a further 1 hour thenallowed to warm to ambient and stirred for 72 hours. The solvent wasremoved by evaporation and the residual oil was poured into ice andextracted with DCM (3×30 ml). Combined the organic extracts and dried bypassing through a hydrophobic frit and evaporated in vacuo to give acolourless oil which contained the title compound.

1H NMR (400 MHz, CDCl₃) δ ppm 1.04-1.27 (m, 11H excess) 1.43-1.64 (m, 5Hexcess) 1.77-1.93 (m, 1H) 3.44-3.55 (m, 1H) 3.59-3.77 (m, 4H)

Intermediate 197: 4-(2-Bromoethyl)-2,2-dimethyltetrahydro-2H-pyran

Prepared similarly to Intermediate 174 from2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethanol.

1H NMR (400 MHz, CDCl₃) δ ppm 1.04-1.12 (m, 1H) 1.14-1.20 (m, 1H)1.20-1.25 (m, 6H) 1.54-1.64 (m, 6H excess) 1.71-1.83 (m, 2H) 1.87-2.01(m, 1H) 3.42-3.49 (m, 2H) 3.62-3.80 (m, 1H)

Intermediate 198:(4E/Z)-2,2-dimethyl-4-{3-[(phenylmethyl)oxy]propylidene}tetrahydro-2H-pyran

To a stirred suspension oftriphenyl{3-[(phenylmethyl)oxy]propyl}phosphonium bromide (23.00 g, 46.8mmol) in THF (60 ml) at −15° C. under nitrogen atmosphere was addedn-butyllithium, 1.6M in hexane (29.3 ml, 46.8 mmol) dropwise over 30mins. The orange/red solution was stirred at −10° C. for 30 mins. Asolution of 2,2-dimethyltetrahydro-4H-pyran-4-one (6 g, 46.8 mmol) inTHF (10 ml) was added dropwise at −10° C. over 25 mins. The reactionmixture was then stirred at −10° C. for 15 mins and then graduallyallowed to warm up to room temperature while stirring under nitrogenatmosphere for 20 hours. 10 ml of ether were added and the suspensionwas filtered on Celite. The Celite was washed with ether (2×40 mL). Thefiltrate was concentrated under vacuum. The residue was purified bychromatography on silica (2×100 g) using a Cyclohexane:Ethyl Acetate0->25% gradient over 40 mins on a Flashmaster II. The fractions wereanalysed by TLC (revealed with a permanganate dip). The desiredfractions were combined and concentrated under vacuum to yield the titlecompound as a colourless oil (5.98 g).

1H NMR (400 MHz, DMSO-d₆) δ ppm 1.97-2.01 (m, 1H) 2.01-2.14 (m, 3H)2.19-2.33 (m, 2H) 3.36-3.44 (m, 2H) 3.48-3.58 (m, 2H) 4.45 (s, 2H)5.09-5.19 (m, 0.6H) 5.26-5.33 (m, 0.4H) 7.22-7.38 (m, 5H)

Intermediate 199: 3-(2,2-Dimethyltetrahydro-2H-pyran-4-yl)-1-propanol

A solution of2,2-dimethyl-4-{3-[(phenylmethyl)oxy]propylidene}tetrahydro-2H-pyran(5.98 g, 22.97 mmol) in ethyl acetate (70 ml) was hydrogenated over 10%palladium on activated carbon (0.733 g, 0.689 mmol) at atmosphericpressure and room temperature. After 16 hours, the mixture was filteredunder vacuum through Celite, washed through with EtOAc (2×50 mL) and thefiltrate was evaporated to dryness to give a yellowish mobile oil. ¹HNMR showed that most of the benzyl group had been hydrogenated but thedouble bond was still present. The residue was dissolved in ethylacetate (70 ml) and was hydrogenated over 10% palladium on activatedcarbon (1.1 g) at atmospheric pressure and room temperature. After 16hours, the mixture was filtered under vacuum through Celite, washedthrough with EtOAc (2×50 mL) and the filtrate was evaporated to drynessto give a yellowish mobile oil. The residue was purified bychromatography on silica (100 g) using a cyclohexane:ethyl acetate0->50% gradient over 40 mins on a Flashmaster II. The desired fractions(analysed with a permanganate dip) were combined and concentrated undervacuum to give the title compound as a pale yellow oil (2.17 g).

1H NMR (400 MHz, CDCl₃) δ ppm 1.01-1.31 (m, 12H excess) 1.50-1.74 (m, 6Hexcess) 3.59-3.69 (m, 3H) 3.70-3.78 (m, 1H)

Intermediate 200: 4-(3-Bromopropyl)-2,2-dimethyltetrahydro-2H-pyran

Prepared similarly to Intermediate 174 from4-(3-bromopropyl)-2,2-dimethyltetrahydro-2H-pyran.

1H NMR (400 MHz, CDCl₃) δ ppm 0.98-1.27 (m, 9H excess) 1.27-1.37 (m, 2H)1.45-1.71 (m, 3H) 1.79-1.91 (m, 2H) 3.31-3.43 (m, 4H) 3.56-3.66 (m, 2H)3.67-3.75 (m, 2H)

Intermediate 201:2,2-Dimethyl-4-{(1E)-4-[(phenylmethyl)oxy]-1-buten-1-yl}tetrahydro-2H-pyran

To a stirred suspension oftriphenyl{3-[(phenylmethyl)oxy]propyl}phosphonium bromide (20.74 g, 42.2mmol) in THF (60 ml) at −15° C. under a nitrogen atmosphere was addedn-butyl lithium, 1.6M in hexane (26.4 ml, 42.2 mmol) dropwise over 30mins. The orange/red solution was stirred at −10° C. for 30 mins. Asolution of 2,2-dimethyltetrahydro-2H-pyran-4-carbaldehyde (6 g, 42.2mmol) in THF (10 ml) was added dropwise at −10° C. over 25 mins. Thereaction mixture was then stirred at −10° C. for 15 mins and thengradually allowed to warm up to room temperature while stirring undernitrogen atmosphere for 16 hours. Ether (10 ml) was added and thesuspension was filtered on Celite. The Celite was washed with ether(2×40 mL). The filtrate was concentrated under vacuum. The residue waspurified by chromatography on silica (2×100 g) using a cyclohexane:ethylacetate 0->25% gradient over 40 mins on a Flashmaster II. The fractionswere analysed by TLC (revealed with a permanganate dip). The desiredfractions were combined and concentrated under vacuum to yield the titlecompound as a colourless oil (7.46 g).

1H NMR (400 MHz, DMSO-d₆) δ ppm 1.01-1.20 (m, 8H) 1.31-1.40 (m, 2H)2.27-2.36 (m, 2H) 2.59-2.72 (m, 1H) 3.39-3.47 (m, 2H) 3.51-3.58 (m, 2H)4.42-4.48 (m, 2H) 5.13-5.42 (m, 2H) 7.23-7.38 (m, 5H)

Intermediate 202: 4-(2,2-Dimethyltetrahydro-2H-pyran-4-yl)-1-butanol

A solution of2,2-dimethyl-4-{4-[(phenylmethyl)oxy]-1-buten-1-yl}tetrahydro-2H-pyran(7.46 g, 27.2 mmol) I ethyl acetate (70 ml) was hydrogenated over 10%palladium on activated carbon (1.447 g, 1.359 mmol) at atmosphericpressure and room temperature. After 16 hours, the mixture was filteredunder vacuum through Celite, washed through with EtOAc (2×50 ml) and thefiltrate was evaporated to dryness to give a yellowish mobile oil (4.8g). The residue was purified by chromatography on silica (70 g) using acyclohexane:ethyl acetate 0->50% gradient over 40 mins using aFlashmaster II. The desired fractions (analysed with a permanganate dip)were combined and concentrated under vacuum to give the title compoundas a yellow oil (1.675 g).

1H NMR (400 MHz, CDCl₃) δ ppm 1.00-1.29 (m, 10H) 1.33-1.44 (m, 2H)1.50-1.71 (m, 5H) 3.62-3.68 (m, 3H) 3.70-3.76 (m, 1H)

Intermediate 203: 4-(4-Bromobutyl)-2,2-dimethyltetrahydro-2H-pyran

Prepared similarly to Intermediate 174 from4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)-1-butanol.

1H NMR (400 MHz, CDCl₃) δ ppm 1.00-1.29 (m, 10H) 1.39-1.71 (m, 5H)1.79-1.90 (m, 2H) 3.37-3.47 (m, 2H) 3.59-3.78 (m, 2H)

Intermediate 204:2-{[(1R)-1-Methylbutyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

Sodium t-butoxide (27.3 g, 284 mmol) was added portionwise to(R)-2-pentanol (140 ml) at room temperature, the mixture was stirreduntil homogeneous.2-Chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine (18.0 g, 71.0mmol) was added and the reaction mixture heated at 50° C. for 160 hours.The reaction was cooled to room temperature and partitioned betweenethyl acetate (500 ml) and water (500 ml). The organic phase was washedwith saturated sodium chloride solution (100 ml), dried (MgSO₄),filtered and evaporated. The residue was triturated with ether and thesolid material filtered. The precipitate was re-washed with ether andthe filtrates combined and evaporated. The crude material (ca. 10 g) wasdissolved in DMSO:methanol (1:1) and purified on a reverse phase (C18)column (330 g) using a gradient of 25-65% acetonitrile (+0.1% TFA)-water(+0.1% TFA) over 8 column volumes, the fractions were immediatelyneutralised with saturated aqueous sodium carbonate solution.Appropriate fractions were combined and partitioned betweendichloromethane and saturated aqueous sodium hydrogen carbonate. Theorganic phase was dried (MgSO₄), filtered and evaporated to give thetitle compound as a pale cream foam (5.05 g).

LCMS (Method A): t_(RET)=2.95 min; MH⁺ 306

Intermediate 205:8-Bromo-2-{[(1R)-1-methylbutyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

2-{[(1R)-1-methylbutyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(5.05 g, 16.54 mmol) was dissolved in chloroform (30 ml) and cooled to0° C. To this solution N-bromosuccinimide (3.24 g, 18.19 mmol) was addedportionwise keeping the temperature below 2° C. This gave a dark greensolution which was stirred at 0° C. for 30 minutes before allowing towarm to room temperature and stirring for 6 hours. The reaction mixturewas washed with water (2×50 ml) and the layers separated usinghydrophobic frit. The organic layer was concentrated to give a darkbrown gum which was dissolved in dichloromethane and purified bychromatography silica (100 g) using a 0-50% gradient of ethylacetate-cyclohexane over 60 mins on a Flashmaster II. The appropriatefractions were combined and evaporated in vacuo to give the titlecompound as a yellow foam (5.23 g).

LCMS (Method B): t_(RET)=1.21 min; MH⁺ 384/386

Intermediate 206:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

8-bromo-2-{[(1R)-1-methylbutyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(5.23 g, 13.61 mmol) was heated to reflux with 25% sodium methoxide inmethanol (8.8 ml, 13.61 mmol) and methanol (40 ml) for 4 hours. Thereaction mixture was concentrated under reduced pressure and partitionedbetween saturated ammonium chloride (100 ml) and dichloromethane (100ml). The aqueous was washed with further dichloromethane (100 ml) andthe combined organics passed through a hydrophobic frit and concentratedto give the title compound as a pale yellow foam (4.80 g).

LCMS (Method B): t_(RET)=1.14 min; MH⁺ 336

Intermediate 207:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate

To a solution of2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(4.8 g, 14.31 mmol) in methanol (100 ml) was added trifluoroacetic acid(8 ml, 104 mmol). The reaction mixture was stirred at room temperaturefor 72 hours. The solvent was removed in vacuo to give a pale yellowsolid which was suspended in ethyl acetate (30 ml). The precipitate wasfiltered off and washed with further ethyl acetate until the filtratewas colourless. The remaining solid was dried by air and then in vacuoto give the title compound as a cream solid (3.85 g).

LCMS (Method B): t_(RET)=0.82 min; MH⁺ 252

Intermediate 208:2-{[(1S)-1-Methylbutyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

Prepared similarly to Intermediate 204 using (2S)-pentanol.

LCMS (Method A): t_(RET)=2.95 min; MH⁺ 306

Intermediate 209:8-Bromo-2-{[(1S)-1-methylbutyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

Prepared similarly to Intermediate 205 from2-{[(1S)-1-Methylbutyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.30 min; MH⁺ 384/386

Intermediate 210:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine

Prepared similarly to Intermediate 206 from8-Bromo-2-{[(1S)-1-methylbutyl]oxy}-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.08 min; MH⁺ 336

Intermediate 211:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate

Prepared similarly to Intermediate 207 from2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.31 min; MH⁺ 252

Intermediate 212:N²-Butyl-8-(methyloxy)-9-[3-(tetrahydro-2-furanyl)propyl]-9H-purine-2,6-diamine

Prepared similarly to Intermediate 216 fromN²-butyl-8-(methyloxy)-3H-purine-2,6-diamine trifluoroacetate and2-(3-bromopropyl)tetrahydrofuran.

LCMS (Method A): t_(RET)=2.53 min; MH⁺=349

Intermediate 213:N²-Butyl-8-(methyloxy)-9-[4-(tetrahydro-2-furanyl)butyl]-9H-purine-2,6-diamine

2-(Butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate (120 mg,0.342 mmol) was heated with potassium carbonate (189 mg, 1.366 mmol) indry DMF (5 ml) at 60° C. for 1 hour and then cooled to room temperature.2-(4-Bromobutyl)tetrahydrofuran (82 mg, 0.394 mmol) was added and thereaction mixture heated at 50° C. under nitrogen for 16 hours and thenpartitioned between water (2 ml) and DCM (5 ml). The aqueous layer wasfurther extracted with DCM (2×5 ml) and the combined organic layers weredried by passage through a hydrophobic frit and evaporated to drynessusing a nitrogen blowdown unit. The residue was dissolved in methanol(0.6 ml) and purified by mass directed autopreparation. Productcontaining fractions were combined and evaporated to dryness in anitrogen blowdown apparatus to give the title compound (76 mg).

LCMS (Method B): t_(RET)=1.20 min; MH⁺=363

Intermediate 214:N²-Butyl-8-(methyloxy)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-9H-purine-2,6-diamine

Prepared similarly to Intermediate 215 fromN²-butyl-8-(methyloxy)-3H-purine-2,6-diamine trifluoroacetate and(3R)-3-(2-Bromoethyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.07 min; MH⁺=335

Intermediate 215:N²-Butyl-8-(methyloxy)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-9H-purine-2,6-diamine

N²-Butyl-8-(methyloxy)-3H-purine-2,6-diamine (157 mg, 0.447 mmol) washeated in dry DMF (3 ml) with potassium carbonate (232 mg, 1.675 mmol)at 60° C. for one hour. (3S)-3-(2-Bromoethyl)tetrahydrofuran (100 mg,0.558 mmol) in dry DMF (2 ml) was added and the mixture stirred andheated to 60° C. under nitrogen for 4 hours. The mixture was cooled toroom temperature, quenched into water (40 ml) and extracted with ethylacetate (3×25 ml). The organic extracts were combined, dried by passagethrough a hydrophobic frit and concentrated under vacuum. The residuewas dissolved in 1:1 MeOH:DMSO and purified by mass directedautopreparation. The desired fractions were combined and concentratedusing a nitrogen blowdown unit to give the title compound as a whitesolid (119 mg).

LCMS (Method B): t_(RET)=1.00 min; MH⁺=335

Intermediate 216:N²-Butyl-8-(methyloxy)-9-[3-(tetrahydro-3-furanyl)propyl]-9H-purine-2,6-diamine

N²-Butyl-8-(methyloxy)-3H-purine-2,6-diamine trifluoroacetate (150 mg,0.428 mmol) was heated in dry DMF (2.5 ml) at 60° C. for 1 hour withpotassium carbonate (237 mg, 1.713 mmol). The reaction mixture wascooled to room temperature and 3-(3-bromopropyl)tetrahydrofuran (99 mg,0.514 mmol) was added. The mixture was then heated at 50° C. overnight.The reaction mixture was quenched with water (50 ml) and extracted withethyl acetate (3×25 ml). The combined organic layers were separated andthen dried by passage through a hydrophobic frit and evaporated todryness. The residue was dissolved in 1:1 MeOH:DMSO (2.8 ml) andpurified by mass directed autopreparation. Product containing fractionswere evaporated under a stream of nitrogen in a blowdown apparatus togive the title compound as a clear gum (84 mg).

LCMS (Method B): t_(RET)=1.14 min; MH⁺=349

Intermediate 217:N²-Butyl-8-(methyloxy)-9-[4-(tetrahydro-3-furanyl)butyl]-9H-purine-2,6-diamine

Prepared similarly to Intermediate 216 fromN²-butyl-8-(methyloxy)-3H-purine-2,6-diamine trifluoroacetate and3-(4-bromobutyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.05 min; MH⁺=363

Intermediate 218:N²-Butyl-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-9H-purine-2,6-diamine

Prepared similarly to Intermediate 216 fromN²-butyl-8-(methyloxy)-3H-purine-2,6-diamine trifluoroacetate and2-(3-bromopropyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.16 min; MH⁺=363

Intermediate 219:N²-Butyl-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-9H-purine-2,6-diamine

Prepared similarly to Intermediate 220 fromN²-butyl-8-(methyloxy)-3H-purine-2,6-diamine trifluoroacetate and2-(4-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.50 min; MH⁺=377

Intermediate 220:N²-Butyl-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-9H-purine-2,6-diamine

A mixture of N²-butyl-8-(methyloxy)-3H-purine-2,6-diamine (150 mg, 0.429mmol) and potassium carbonate (237 mg, 1.718 mmol) in dry DMF (5 ml) wasstirred at 60° C. for 1 hour under an atmosphere of nitrogen and thencooled to room temperature. 4-(3-Bromopropyl)tetrahydro-2H-pyran (0.087ml, 0.515 mmol) was added and the mixture stirred at 50° C. overnight.The mixture was cooled and partitioned between 1:1 ethyl acetate:DCM (10ml) and water (10 ml). The organic phase was separated using ahydrophobic frit and evaporated under a stream of nitrogen using ablowdown apparatus. The residue was dissolved in 1:1 methanol:DCM (2.8ml) and purified by mass directed autopreparation. Product containingfractions were evaporated under a stream of nitrogen to give the titlecompound as a white solid (93.13 mg).

LCMS (Method B): t_(RET)=1.27 min; MH⁺=363

Intermediate 221:N²-Butyl-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-9H-purine-2,6-diamine

Prepared similarly to Intermediate 220 fromN²-butyl-8-(methyloxy)-3H-purine-2,6-diamine trifluoroacetate and4-(4-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.38 min; MH⁺=377

Intermediate 222:N²-Butyl-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-8-(methyloxy)-9H-purine-2,6-diamine

A mixture of N²-butyl-8-(methyloxy)-3H-purine-2,6-diaminetrifluoroacetate, (0.2 g, 0.571 mmol) and anhydrous potassium carbonate(0.316 g, 2.284 mmol) in DMF (2.5 ml) was heated at 50° C. for 1 hour.The mixture was cooled to room temperature and4-(2-bromoethyl)-2,2-dimethyltetrahydro-2H-pyran (0.152 g, 0.685 mmol)was added and the mixture heated at 50° C. for 18 hours. The mixture wasquenched with water (2 ml) and then extracted with DCM (2×5 ml). The DCMwas separated through a hydrophobic frit and evaporated by blowing downunder a stream of nitrogen. DMSO:MeOH (1:1) was added to the residue andthe resulting precipitate was collected by filtration, washed withmethanol and dried in vacuo to give the title compound as a white solid(136 mg).

LCMS (Method A): t_(RET)=2.65 min; MH⁺=377

Intermediate 223:N²-Butyl-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-8-(methyloxy)-9H-purine-2,6-diamine

A mixture of N²-butyl-8-(methyloxy)-3H-purine-2,6-diaminetrifluoroacetate (149 mg, 0.425 mmol) and potassium carbonate (294 mg,2.126 mmol) in DMF (2 ml) was stirred and heated at 60° C. undernitrogen for one hour. 4-(3-Bromopropyl)-2,2-dimethyltetrahydro-2H-pyran(125 mg, 0.532 mmol) in dry DMF (1 ml) was added and the mixture heatedat 60° C. under nitrogen for a further 2.5 hours. The reaction mixturewas cooled to room temperature, quenched into water (10 ml) andextracted with DCM:EtOAc (1:1, 2×20 ml). The organic extracts werecombined, dried by passage through a hydrophobic frit and concentratedunder vacuum. The residue was purified by mass directed autopreparation.Product containing fractions were combined and evaporated to give thetitle compound (40 mg).

LCMS (Method A): t_(RET)=2.81 min; MH⁺=391

Intermediate 224:N²-Butyl-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-8-(methyloxy)-9H-purine-2,6-diamine

Prepared similarly to Intermediate 223 fromN²-butyl-8-(methyloxy)-3H-purine-2,6-diamine trifluoroacetate and4-(4-bromobutyl)-2,2-dimethyltetrahydro-2H-pyran but conducting thealkylation over 1.5 hours at 60° C.

LCMS (Method A): t_(RET)=2.95 min; MH⁺=405

Intermediate 225:2-(Butyloxy)-8-(methyloxy)-9-[3-(tetrahydro-2-furanyl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-(butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate and2-(3-bromopropyl)tetrahydrofuran.

LCMS (Method A): t_(RET)=2.96 min; MH⁺=350

Intermediate 226:2-(Butyloxy)-8-(methyloxy)-9-[4-(tetrahydro-2-furanyl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 213 from2-(butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate and2-(4-bromobutyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.14 min; MH⁺=364

Intermediate 227:2-(Butyloxy)-8-(methyloxy)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine

Prepared similarly to Intermediate 215 from2-(butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate and(3R)-3-(2-bromoethyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=0.99 min; MH⁺=336

Intermediate 228:2-(Butyloxy)-8-(methyloxy)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine

Prepared similarly to Intermediate 215 from2-(butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate and(3S)-3-(2-bromoethyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=0.99 min; MH⁺=336

Intermediate 229:2-(Butyloxy)-8-(methyloxy)-9-[3-(tetrahydro-3-furanyl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-(butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate and3-(3-bromopropyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.04 min; MH⁺=350

Intermediate 230:2-(Butyloxy)-8-(methyloxy)-9-[4-(tetrahydro-3-furanyl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-(butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate and3-(4-bromobutyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.11 min; MH⁺=364

Intermediate 231:2-(Butyloxy)-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-(butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate and2-(3-bromopropyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.19 min; MH⁺=364

Intermediate 232:2-(Butyloxy)-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-(butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate and2-(4-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.25 min; MH⁺=378

Intermediate 233:2-(Butyloxy)-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-3-yl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 213 from2-(butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate and3-(3-bromopropyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.13 min; MH⁺=364

Intermediate 234:2-(Butyloxy)-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 243 from2-(butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate and3-(4-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method A): t_(RET)=3.27 min; MH⁺=378

Intermediate 235:2-(Butyloxy)-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-(butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate and4-(3-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.11 min; MH⁺=364

Intermediate 236:2-(Butyloxy)-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-(butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate and4-(4-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.18 min; MH⁺=378

Intermediate 237:2-(Butyloxy)-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-8-(methyloxy)-9H-purin-6-amine

A mixture of 2-(butyloxy)-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate (0.2 g, 0.569 mmol) and anhydrous potassium carbonate(0.315 g, 2.277 mmol) in DMF was heated at 60° C. for 1 hour. Themixture was cooled to room temperature and4-(2-bromoethyl)-2,2-dimethyltetrahydro-2H-pyran (0.151 g, 0.683 mmol)was added and the mixture heated at 50° C. for 18 hours. The mixture wasquenched with water (2 ml) and extracted with DCM (2×5 ml). The DCM wasseparated through a hydrophobic frit and evaporated by blowing downunder a stream of nitrogen. Addition of DMSO:MeOH (1:1) gave aprecipitate which was collected by filtration, washed with methanol anddried in vacuo to give the title compound (29 mg).

LCMS (Method A): t_(RET)=3.10 min; MH⁺=378

Evaporation of the filtrate to dryness and trituration of the residuewith DMSO:MeOH (1:1, 0.5 ml) gave a second batch of material (101 mg).

LCMS (Method A): t_(RET)=3.10 min; MH⁺=378

Intermediate 238:2-(Butyloxy)-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-8-(methyloxy)-9H-purin-6-amine

Prepared similarly to Intermediate 224 from2-(butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate and4-(3-bromopropyl)-2,2-dimethyltetrahydro-2H-pyran.

LCMS (Method A): t_(RET)=3.25 min; MH⁺=392

Intermediate 239:2-(Butyloxy)-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-8-(methyloxy)-9H-purin-6-amine

Prepared similarly to Intermediate 224 from2-(butyloxy)-8-(methyloxy)-1H-purin-6-amine trifluoroacetate and4-(4-bromobutyl)-2,2-dimethyltetrahydro-2H-pyran but conducting thealkylation over 1.5 hours at 60° C.

LCMS (Method A): t_(RET)=3.43 min; MH⁺=406

Intermediate 240:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-[2-(tetrahydro-2-furanyl)ethyl]-9H-purin-6-amine

Prepared similarly to Intermediate 213 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(2-bromoethyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.05 min; MH⁺=348

Intermediate 241:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-[3-(tetrahydro-2-furanyl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(3-bromopropyl)tetrahydrofuran.

LCMS (Method A): t_(RET)=2.98 min; MH⁺=362

Intermediate 242:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-[4-(tetrahydro-2-furanyl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 213 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(4-bromobutyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.15 min; MH⁺=376

Intermediate 243:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-[2-(tetrahydro-3-furanyl)ethyl]-9H-purin-6-amine

A mixture of 2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate (0.16 g, 0.450 mmol) and anhydrous potassium carbonate(0.243 g, 1.762 mmol) in DMF (2.5 ml) was heated at 50° C. for 1 hour.The mixture was cooled to room temperature and3-(2-bromoethyl)tetrahydrofuran (0.095 g, 0.528 mmol) was added and themixture heated at 50° C. for 18 hours. The mixture was quenched withwater (2 ml) and extracted with DCM (2×5 ml). The DCM was separatedthrough a hydrophobic frit and evaporated by blowing down under a streamof nitrogen. The sample was dissolved in 1:1 MeOH:DMSO (3×0.5 ml) andpurified by mass directed autopreparation. Product containing fractionswere evaporated under a stream of nitrogen in a blowdown apparatus togive the title compound as a white solid (98 mg).

LCMS (Method A): t_(RET)=2.80 min; MH⁺=348

Intermediate 244:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine

Prepared similarly to Intermediate 215 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and (3R)-3-(2-bromoethyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.00 min; MH⁺=348

Intermediate 245:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine

Prepared similarly to Intermediate 215 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and (3S)-3-(2-bromoethyl)tetrahydrofuran.

LCMS (Method A): t_(RET)=2.80 min; MH⁺=348

Intermediate 246:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-[3-(tetrahydro-3-furanyl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 3-(3-bromopropyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.04 min; MH⁺=362

Intermediate 247:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-[4-(tetrahydro-3-furanyl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 3-(4-bromobutyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.11 min; MH⁺=376

Intermediate 248:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(2-bromoethyl)tetrahydro-2H-pyran.

LCMS (Method A): t_(RET)=3.12 min; MH⁺=362

Intermediate 249:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(3-bromopropyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.18 min; MH⁺=376

Intermediate 250:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 213 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(4-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method A): t_(RET)=3.27 min; MH⁺=390

Intermediate 251:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 3-(2-bromoethyl)tetrahydro-2H-pyran.

LCMS (Method A): t_(RET)=2.99 min; MH⁺=362

Intermediate 252:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 243 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 3-(4-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method A): t_(RET)=3.28 min; MH⁺=390

Intermediate 253:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-9H-purin-6-amine

Prepared similarly to Intermediate 215 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(2-bromoethyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.04 min; MH⁺=362

Intermediate 254:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 220 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(3-bromopropyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.12 min; MH⁺=376

Intermediate 255:2-[(2-Cyclopropylethyl)oxy]-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 220 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(4-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.19 min; MH⁺=390

Intermediate 256:2-[(2-Cyclopropylethyl)oxy]-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-8-(methyloxy)-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(2-bromoethyl)-2,2-dimethyltetrahydro-2H-pyran.

LCMS (Method A): t_(RET)=3.12 min; MH⁺=390

Intermediate 257:2-[(2-Cyclopropylethyl)oxy]-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-8-(methyloxy)-9H-purin-6-amine

Prepared similarly to Intermediate 223 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(3-bromopropyl)-2,2-dimethyltetrahydro-2H-pyran.

LCMS (Method A): t_(RET)=3.26 min; MH⁺=404

Intermediate 258:2-[(2-Cyclopropylethyl)oxy]-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-8-(methyloxy)-9H-purin-6-amine

Prepared similarly to Intermediate 223 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(4-bromobutyl)-2,2-dimethyltetrahydro-2H-pyranbut conducting the alkylation over 1.5 hours at 60° C.

LCMS (Method A): t_(RET)=3.43 min; MH⁺=418

Intermediate 259:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2-furanyl)ethyl]-9H-purin-6-amine

Prepared similarly to Intermediate 243 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(2-bromoethyl)tetrahydrofuran.

LCMS (Method A): t_(RET)=3.07 min; MH⁺=350

Intermediate 260:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-2-furanyl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 215 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(3-bromopropyl)tetrahydrofuran but conducting thealkylation over 1 hour at 60° C.

LCMS (Method A): t_(RET)=3.00 min; MH⁺=364

Intermediate 261:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and (3R)-3-(2-bromoethyl)tetrahydrofuran.

LCMS (Method A): t_(RET)=2.81 min; MH⁺=350

Intermediate 262:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine

Prepared similarly to Intermediate 215 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and (3S)-3-(2-bromoethyl)tetrahydrofuran but conductingthe alkylation over 1 hour at 60° C.

LCMS (Method A): t_(RET)=2.96 min; MH⁺=350

Intermediate 263:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-3-furanyl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 220 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 3-(3-bromopropyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.13 min; MH⁺=364

Intermediate 264:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-3-furanyl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 220 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 3-(4-bromobutyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.19 min; MH⁺=378

Intermediate 265:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-9H-purin-6-amine

Prepared similarly to Intermediate 243 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(2-bromoethyl)tetrahydro-2H-pyran.

LCMS (Method A): t_(RET)=3.27 min; MH⁺=364

Intermediate 266:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 220 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(3-bromopropyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.26 min; MH⁺=378

Intermediate 267:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 213 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(4-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method A): t_(RET)=3.33 min; MH⁺=392

Intermediate 268:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-9H-purin-6-amine

Prepared similarly to Intermediate 243 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 3-(2-bromoethyl)tetrahydro-2H-pyran.

LCMS (Method A): t_(RET)=3.13 min; MH⁺=364

Intermediate 269:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 243 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 3-(4-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method A): t_(RET)=3.42 min; MH⁺=392

Intermediate 270:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-9H-purin-6-amine

Prepared similarly to Intermediate 215 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(2-bromoethyl)tetrahydro-2H-pyran but conductingthe alkylation over 1 hour at 60° C.

LCMS (Method A): t_(RET)=2.97 min; MH⁺=364

Intermediate 271:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(3-bromopropyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.19 min; MH⁺=378

Intermediate 272:2-{[(1S)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(4-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.26 min; MH⁺=392

Intermediate 273:9-[2-(2,2-Dimethyltetrahydro-2H-pyran-4-yl)ethyl]-2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9H-purin-6-amine

Prepared similarly to Intermediate 243 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(2-bromoethyl)-2,2-dimethyltetrahydro-2H-pyran.

LCMS (Method A): t_(RET)=3.26 min; MH⁺=392

Intermediate 274:9-[3-(2,2-Dimethyltetrahydro-2H-pyran-4-yl)propyl]-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9H-purin-6-amine

Prepared similarly to Intermediate 215 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(3-bromopropyl)-2,2-dimethyltetrahydro-2H-pyranbut conducting the alkylation over 1 hour at 60° C.

LCMS (Method A): t_(RET)=3.37 min; MH⁺=406

Intermediate 275:9-[4-(2,2-Dimethyltetrahydro-2H-pyran-4-yl)butyl]-2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9H-purin-6-amine

Prepared similarly to Intermediate 215 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(4-bromobutyl)-2,2-dimethyltetrahydro-2H-pyranbut conducting the alkylation over 1 hour at 60° C.

LCMS (Method A): t_(RET)=3.44 min; MH⁺=420

Intermediate 276:2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2-furanyl)ethyl]-9H-purin-6-amine

Prepared similarly to Intermediate 290 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(2-bromoethyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.11 min; MH⁺=350

Intermediate 277:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-2-furanyl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 223 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(3-bromopropyl)tetrahydrofuran but conducting thealkylation over 1 hour at 60° C.

LCMS (Method A): t_(RET)=3.00 min; MH⁺=364

Intermediate 278:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and (3R)-3-(2-bromoethyl)tetrahydrofuran.

LCMS (Method A): t_(RET)=2.81 min; MH⁺=350

Intermediate 279:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine

Prepared similarly to Intermediate 223 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and (3S)-3-(2-bromoethyl)tetrahydrofuran but conductingthe alkylation over 1 hour at 60° C.

LCMS (Method A): t_(RET)=2.81 min; MH⁺=350

Intermediate 280:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-3-furanyl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 3-(3-bromopropyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.09 min; MH⁺=364

Intermediate 281:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-3-furanyl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 3-(4-bromobutyl)tetrahydrofuran.

LCMS (Method B): t_(RET)=1.16 min; MH⁺=378

Intermediate 282:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-9H-purin-6-amine

Prepared similarly to Intermediate 213 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(2-bromoethyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.21 min; MH⁺=364

Intermediate 283:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(3-bromopropyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.25 min; MH⁺=378

Intermediate 284:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 213 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 2-(4-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method A): t_(RET)=3.33 min; MH⁺=392?

Intermediate 285:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-9H-purin-6-amine

Prepared similarly to Intermediate 213 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 3-(2-bromoethyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.13 min; MH⁺=364

Intermediate 286:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 213 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 3-(4-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.26 min; MH⁺=392

Intermediate 287:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-9H-purin-6-amine

Prepared similarly to Intermediate 223 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(2-bromoethyl)tetrahydro-2H-pyran but conductingthe alkylation over 1 hour at 60° C.

LCMS (Method A): t_(RET)=2.94 min; MH⁺=364

Intermediate 288:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(3-bromopropyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.16 min; MH⁺=378

Intermediate 289:2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-9H-purin-6-amine

Prepared similarly to Intermediate 216 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(4-bromobutyl)tetrahydro-2H-pyran.

LCMS (Method B): t_(RET)=1.24 min; MH⁺=392

Intermediate 290:9-[2-(2,2-Dimethyltetrahydro-2H-pyran-4-yl)ethyl]-2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9H-purin-6-amine

2-{[(1R)-1-Methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate (100 mg, 0.274 mmol) was heated with potassiumcarbonate (37.8 mg, 0.274 mmol) in dry DMF (2 ml) at 60° C. undernitrogen for 1 hour and then cooled to room temperature.4-(2-Bromoethyl)-2,2-dimethyltetrahydro-2H-pyran (72.6 mg, 0.328 mmol)was added and the reaction mixture heated at 50° C., for 16 hours. LCMSindicated the reaction to be incomplete and more4-(2-bromoethyl)-2,2-dimethyltetrahydro-2H-pyran (35 mg) was added, andthe reaction stirred at 50° C. for a further 5 hours and thenpartitioned between water (2 ml) and DCM (5 ml). The aqueous layer wasfurther extracted with DCM (2×5 ml). The combined organic layers werecombined and dried by passing through a hydrophobic frit and thenevaporated to dryness using a nitrogen blowdown unit. The residue wasdissolved in methanol (0.6 ml) and purified by mass directedautopreparation. Evaporation of the product containing fractions under astream of nitrogen in a blowdown apparatus gave the title compound as awhite solid (92 mg).

LCMS (Method B): t_(RET)=1.19 min; MH⁺=392

Intermediate 291:9-[3-(2,2-Dimethyltetrahydro-2H-pyran-4-yl)propyl]-2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9H-purin-6-amine

Prepared similarly to Intermediate 223 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(3-bromopropyl)-2,2-dimethyltetrahydro-2H-pyranbut conducting the alkylation over 1 hour at 60° C.

LCMS (Method A): t_(RET)=3.27 min; MH⁺=406

Intermediate 292:9-[4-(2,2-Dimethyltetrahydro-2H-pyran-4-yl)butyl]-2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9H-purin-6-amine

Prepared similarly to Intermediate 223 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-1H-purin-6-aminetrifluoroacetate and 4-(4-bromobutyl)-2,2-dimethyltetrahydro-2H-pyranbut conducting the alkylation over 1 hour at 60° C.

LCMS (Method A): t_(RET)=3.44 min; MH⁺=420

Example 16-Amino-2-butoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

2-Butoxy-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(0.22 g) was dissolved in methanol (10 mL) and treated with 4N hydrogenchloride in 1,4-dioxane (1 mL). The reaction was stirred at roomtemperature 16 hours and stripped to give a solid that was suspended inwater (2 mL) before sufficient methanol was added until a solution wasobtained. 2N Sodium hydroxide solution was added to bring to pH 7, andthe solution concentrated until a suspension formed. The white solid wasfiltered and washed with water (2 mL, twice to complete transfer andwash). This was dried under suction and then under vacuum at 50° C. togive the title compound as a white solid (0.189 g).

MS calcd for (C₁₅H₂₃N₅O₃)⁺=321

MS found (electrospray): (M+H)⁺=322

1H NMR ((CD₃)₂SO): 9.86 (1H, s), 6.41 (2H, s), 4.14 (2H, t), 3.81 (2H,m), 3.55 (2H, d), 3.22 (2H, m), 2.03 (1H, m), 1.64 (2H, m), 1.49-1.33(4H, overlapping m), 1.22 (2H, m), 0.92 (3H, t).

Example 26-Amino-2-butoxy-9-(tetrahydro-2H-pyran-2-ylmethyl)-7,9-dihydro-8H-purin-8-one

2-Butoxy-8-methoxy-9-(tetrahydro-2H-pyran-2-ylmethyl)-9H-purin-6-amine(6 mg, ˜85% pure) was dissolved in methanol (1 mL), treated with 4Nhydrogen chloride in 1,4-dioxane (0.5 mL) and stirred for 5 hours atroom temperature. The mixture was stripped to dryness to give the titlecompound (77.8:10.8 by LCMS) as a colourless gum (8 mg).

MS calcd for (C₁₅H₂₃N₅O₃)⁺=321

MS found (electrospray): (M+H)⁺=322

1H NMR (CD₃OD): 4.54 (2H, t), 4.06-3.65 (5H, overlapping m), 1.87-1.83(3H, overlapping m), 1.69 (1H, d), 1.52 (4H, overlapping m), 1.35 (2H,m), 1.01 (3H, t) (NH₂ & NH protons exchanged).

Example 36-Amino-2-butoxy-9-(tetrahydrofuran-2-ylmethyl)-7,9-dihydro-8H-purin-8-one

To 2-butoxy-8-methoxy-9H-purin-6-amine trifluoroacetate salt (0.20 g) indry DMF (5 mL) was added anhydrous potassium carbonate (0.315 g). Thiswas heated to 60° C. for 1 hour and then cooled to room temperature.Tetrahydrofurfuryl bromide (65 uL) was added and the reaction mixturewas then heated to 50° C. overnight. The reaction was quenched withwater and extracted with ethyl acetate (twice). The organic phase wasseparated, combined and dried by passing through a hydrophobic frit.Evaporation of the organic phase and purification of the oil so formedby silica chromatography (40 g) (ISCO) eluting with 0-100% ethylacetate:cyclohexane and then 0-10% methanol:ethyl acetate then methanolgave a gum. This gum was dissolved in methanol (5 mL) and treated with4N hydrogen chloride in 1,4-dioxane (1 mL) and stirred overnight at roomtemperature. The reaction mixture was stripped to dryness to give a gum(˜44 mg) that was purified by MDAP to give the title compound(slower-running isomer by LCMS) as a white solid (15.2 mg).

MS calcd for (C₁₄H₂₁N₅O₃)⁺=307

MS found (electrospray): (M+H)⁺=308

1H NMR (CD₃OD): 4.36 (1H, m), 4.27 (2H, t), 3.90 (2H, m), 3.75 (2H, d),2.00 (2H, m), 1.90 (1H, m), 1.73 (3H, overlapping m), 1.48 (2H, m), 0.98(3H, t) (NH₂ and NH exchanged).

Example 46-Amino-2-butylamino-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution ofN²-butyl-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine-2,6-diamine(310 mg) in dry methanol (30 ml) at room temperature and under nitrogenwas added 4.0M hydrogen chloride in 1,4-dioxane (5.5 ml) in one go. Thereaction was left to stir at room temperature for 16 hours. The reactionwas neutralised by the addition of 2.0M sodium hydroxide solution andconcentrated in vacuo. The residue was taken up in water (10 ml) and thesolid filtered and dried on the rotary evaporator (60° C.) for 30minutes. This afforded the title compound as a solid (170 mg).

MS calcd for (C₁₅H₂₄N₆O₂)⁺=320

MS found (electrospray): (M+H)⁺=321

¹H NMR ((CD₃)₂SO): δ 9.82 (1H, s), 6.16 (1H, t), 6.09 (2H, s), 3.81 (2H,m), 3.50 (2H, d), 3.21 (2H, m), 3.16 (2H, m), 2.03 (1H, m), 1.44 (4H,m), 1.29 (2H, m), 1.22 (2H, m), 0.88 (3H, t).

Example 4, Alternative Procedure6-Amino-2-(butylamino)-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

N²-Butyl-8-(methoxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine-2,6-diamine(5.16 g) was dissolved in methanol (50 mL) to give an orange solution.To this solution was then added 4N hydrogen chloride in 1,4-dioxane (5mL). The resultant orange solution was stirred at ambient temperature(˜22° C.) for ˜17 hours. The reaction mixture was examined by LCMS andthis showed the reaction had not proceeded to completion. To thereaction mixture was then added a further aliquot of 4N hydrogenchloride in 1,4-dioxane (5 mL) and the reaction mixture was stirred fora further 5.25 hours. Examination of the reaction mixture by LCMS showedreaction nearly complete with a small quantity ofN²-butyl-8-(methoxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine-2,6-diamineremaining. The reaction was evaporated under reduced pressure to give alight tan solid to avoid undesired reaction/decomposition through thereaction being left unattended over weekend. On resuming the experiment,the material was re-dissolved in methanol (50 mL) to give an orangesolution to which was then added 4N hydrogen chloride in 1,4-dioxane (5mL). The reaction mixture was then stirred at ambient temperature (˜20°C.) for 1.6 hours after which the reaction was found to be complete byLCMS.

The reaction mixture was then evaporated under reduced pressure to givea light tan-solid. The material was suspended in a mixture of water (10mL) and methanol (60 mL) and then sonicated to give a finely-dividedsuspension before 2M sodium hydroxide solution was added gradually toneutralise (a further volume of water (10 mL) was added when thesuspension began to thicken).

The resultant suspension was filtered under suction and the filter-cakewashed with water (30 mL) before being air-dried under suction to givean off-white solid. The filtrate was evaporated under suction to give alight-tan solid which was suspended in water (10 mL) and isolated byfiltration under suction. This solid then washed with water:methanol (10mL, 1:1 v/v) to give a light-tan solid which was air-dried under suctionto give (˜0.3 g). Combined solids were then dried under vacuo (50° C.)overnight until a free-flowing off-white solid (4.69 g) was obtained.

This material (4.69 g) was added to a round bottom flask (250 mL)equipped with a magnetic stirrer bar. To the round bottom flask was thenadded absolute ethanol (94 mL). The resultant suspension was heatedgently with stirring until the solid dissolved. Water (94 mL) was thenadded and a precipitate formed. The resultant suspension was then heated(round bottom flask now equipped with a reflux condenser) (external, 95°C.) until the solid re-dissolved. Heating was continued for 5 minutes,before the heat source was removed and allowed to cool with stirring.The resultant solid was then isolated by filtration and washed usingabsolute ethanol:water (50 mL, 1:1 v/v). The resultant filter-cake wasthen air-dried under suction before being dried to constant weight undervacuo (50° C.) over ˜24 hours, this gave the title compound as anoff-white solid (3.57 g).

MS calcd for (C₁₅H₂₄N₆O₂)⁺=320

MS found (electrospray): (M+H)⁺=321

1H NMR ((CD₃)₂SO): 10.56 (1H, s), 7.77 (3H, broad s), 3.87-3.78 (2H, m),3.61-3.53 (2H, m), 3.34-3.26 (2H, m), 3.26-3.18 (2H, m), 2.09-1.94 (1H,m), 1.59-1.44 (4H, overlapping m), 1.40-1.29 (2H, m), 1.29-1.14 (2H, m),0.95-0.87 (3H, m).

Example 56-Amino-2-butylamino-9-(tetrahydro-2H-pyran-2-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution ofN²-butyl-8-methoxy-9-(tetrahydro-2H-pyran-2-ylmethyl)-9H-purine-2,6-diaminein dry methanol (5 ml) at room temperature and under nitrogen was added4.0M hydrogen chloride in 1,4-dioxane (1.5 ml) in one go. The reactionwas left to stir at room temperature overnight. The reaction wasconcentrated in vacuo and the product purified by MDAP. This affordedthe title compound 6 mg (slower-running on MDAP).

MS calcd for (C₁₅H₂₄N₆O₂)⁺=320

MS found (electrospray): (M+H)⁺=321

¹H NMR ((CD₃)₂SO): δ 10.71 (1H, s), 7.91 (3H, br. s), 3.79-3.85 (1H, m),3.71-3.78 (1H, m), 3.62-3.71 (1H, m), 3.54-3.60 (1H, m), 3.26-3.38 (2H,m), 3.19-3.27 (1H, m), 1.70-1.80 (1H, m), 1.53-1.59 (1H, m), 1.49-1.54(2H, m), 1.43 (3H, s), 1.29-1.39 (2H, m), 1.12-1.25 (1H, m), 0.90 (3H,t).

Example 66-Amino-2-butylamino-9-(tetrahydrofuran-2-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of N²-butyl-8-methoxy-9H-purine-2,6-diaminetrifluoroacetic acid salt (400 mg) in dry N,N-dimethylformamide (6 ml)at room temperature and under nitrogen was added potassium carbonate(630 mg) in one go. The reaction was stirred at 60° C. for 1.5 hours andthen cooled to 40° C. 2-(bromomethyl)tetrahydrofuran (156 μl) was addedin one go and the reaction heated to 50° C. overnight and then at 90° C.for 2 hours. The reaction was diluted with ethyl acetate (20 ml) andwashed with water (10 ml). The organic layer was separated andconcentrated in vacuo. The product was semi-purified by MDAP to afford amixture. To this mixture, in dry methanol (5 ml) at room temperature andunder nitrogen was added 4.0M hydrogen chloride in 1,4-dioxane (1.5 ml)in one go. The reaction was left to stir at room temperature overnight.The reaction was concentrated in vacuo and the product purified by MDAP(slower-running isomer). This afforded the title compound as a whitesolid (15 mg).

MS calcd for (C₁₄H₂₂N₆O₂)⁺=306

MS found (electrospray): (M+H)⁺=307

¹H NMR ((CD₃)₂SO): δ 10.69 (1H, s), 7.82 (3H, br. s), 4.18 (1H, m),3.67-3.79 (2H, m), 3.56-3.64 (2H, m), 3.28 (2H, s), 1.76-1.92 (3H, m),1.65 (1H, m), 1.52 (2H, m), 1.32 (2H, m), 0.88 (3H, t).

Example 76-Amino-2-butylamino-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one

To a solution of N²-butyl-8-methoxy-9H-purine-2,6-diaminetrifluoroacetic acid salt (100 mg) in dry N,N-dimethylformamide (1 ml)at room temperature and under nitrogen was added potassium carbonate(158 mg) in one go. The reaction was stirred at 60° C. for 1.5 hours andthen cooled to 50° C. A solution of 4-(2-bromoethyl)tetrahydro-2H-pyran(60 mg) in dry N,N-dimethylformamide (0.5 ml) was added in one go andthe reaction heated at 50° C. overnight. The reaction was diluted withethyl acetate (15 ml) and washed with water (5 ml). The organic layerwas separated and concentrated in vacuo. The product was purified by C₁₈reverse phase chromatography using water (0.1% formic acid)-acetonitrile(0.05% formic acid) as eluant (20-60%) to afford a yellow viscous oil(47 mg) that was dissolved in dry methanol (4 ml) at room temperatureand under nitrogen was added 4.0M hydrogen chloride in 1,4-dioxane (0.8ml) in one go. The reaction was left to stir at room temperatureovernight. The reaction was neutralised by the addition of 2.0M sodiumhydroxide solution and concentrated in vacuo. The residue was taken upin water (5 ml) and the solid filtered and dried in vacuo (60° C.) for30 minutes. This afforded the title compound as a beige solid (23 mg).

MS calcd for (C₁₆H₂₆N₆O₂)⁺=334

MS found (electrospray): (M+H)⁺=335

¹H NMR ((CD₃)₂SO): δ 9.78 (1H, s), 6.08-6.21 (3H, br. s), 3.80 (2H, m),3.65 (2H, t), 3.21 (2H, m), 3.16 (2H, m), 1.66 (2H, m), 1.57 (2H, m),1.36-1.49 (3H, m), 1.29 (2H, m), 1.13 (2H, m), 0.88 (3H, t).

Example 86-Amino-2-butylamino-9-(tetrahydrofuran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of N²-butyl-8-methoxy-9H-purine-2,6-diaminetrifluoroacetic acid salt (100 mg) in dry N,N-dimethylformamide (1 ml)at room temperature and under nitrogen was added potassium carbonate(158 mg) in one go. The reaction was stirred at 60° C. for 1.5 hours andthen cooled to 50° C. A solution of 3-(bromomethyl)tetrahydrofuran (52mg) in dry N,N-dimethylformamide (0.5 ml) was added in one go and thereaction heated at 50° C. overnight. The reaction was diluted with ethylacetate (15 ml) and washed with water (5 ml). The organic layer wasseparated and concentrated in vacuo. The product was semi-purified byC₁₈ reverse phase chromatography using water (containing 0.1% formicacid)-acetonitrile (containing 0.05% formic acid) as eluant (10-45%) togive a yellow oil (32 mg) that was dissolved in dry methanol (3 ml) atroom temperature and under nitrogen was added 4.0M hydrogen chloride in1,4-dioxane (0.6 ml) in one go. The reaction was left to stir at roomtemperature overnight. The reaction was neutralised by the addition of2.0M sodium hydroxide solution and concentrated in vacuo. The residuewas taken up in water (5 ml) and the solid filtered and dried in vacuo(60° C.) for 15 minutes. This afforded the title compound as a whitesolid (20 mg).

MS calcd for (C₁₄H₂₂N₆O₂)⁺=306

MS found (electrospray): (M+H)⁺=307

¹H NMR ((CD₃)₂SO): δ 9.73 (1H, s), 6.17 (1H, m), 6.04 (1H, m), 3.74 (2H,m), 3.56-3.64 (4H, m), 3.53 (1H, m), 3.16 (2H, m), 2.69 (1H, m), 1.85(1H, m), 1.64 (1H, m), 1.46 (2H, m), 1.29 (2H, m), 0.87 (3H, t).

Example 8, Alternative Method6-Amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one

N²-Butyl-8-(methoxy)-9-(tetrahydro-3-furanylmethyl)-9H-purine-2,6-diamine(98 mg) was dissolved in methanol (2 mL). To the resultant solution wasadded 4N hydrogen chloride in 1,4-dioxane (0.5 mL). The reaction mixturewas then stirred at ambient temperature until completion (monitored byLCMS) over 2.5 hours. The reaction mixture was then evaporated underreduced pressure to give an oil. To this oil was added water (2 mL) andmethanol (2 mL). The resultant solution was then neutralised using 2Msodium hydroxide solution. Further water (5 mL) was added when theproduct precipitated (pH 4-5). The white solid was isolated byfiltration under suction and then washed with water (5 mL). The filtercake was then air-dried under suction to give (68 mg) that was dissolvedin ethanol (2 mL). To this solution was added water (2 mL) to give aprecipitate. The resultant suspension was heated (90° C., external) toreflux to give a solution. The resultant solution was refluxed for a fewminutes before being allowed to cool to ambient room temperature to givea flocculent white solid. This solid was isolated by filtration undersuction and the residues transferred using water (8 mL). The filter cakewas air-dried under suction and was then dried under vacuo at 50° C. for4 hours to give a white solid which was then transferred to a vial anddried further at 50° C. (16 hours) to give 55 mg of the title compoundas a white solid.

MS calcd for (C₁₄H₂₂N₆O₂)⁺=306

MS found (electrospray): (M+H)⁺=307

¹H NMR ((CD₃)₂SO): δ 9.55 (1H, br s), 6.11-6.19 (1H, m), 5.95 (2H, brs), 3.80-3.70 (1H, m), 3.66-3.56 (4H, m), 3.56-3.49 (1H, m), 3.16 (2H,q), 2.76-2.63 (1H, m), 1.91-1.80 (1H, m), 1.69-1.59 (1H, m), 1.52-1.41(2H, m), 1.36-1.22 (2H, m), 0.88 (3H, t).

Example 96-Amino-2-butylamino-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution ofN²-butyl-8-methoxy-9-(tetrahydro-2H-pyran-3-ylmethyl)-9H-purine-2,6-diamine(45 mg) in dry methanol (3 ml) at room temperature and under nitrogenwas added 4.0M hydrogen chloride in 1,4-dioxane (0.7 ml) in one go. Thereaction was left to stir at room temperature for 3 hours. The reactionwas neutralised by the addition of 2.0M sodium hydroxide solution andconcentrated in vacuo. The residue was taken up in water (5 ml) and thesolid filtered and dried in vacuo (60° C.) for 30 minutes. This affordedthe title compound as a solid (25 mg).

MS calcd for (C₁₅H₂₄N₆O₂)⁺=320

MS found (electrospray): (M+H)⁺=321

¹H NMR ((CD₃)₂SO): δ 9.59 (1H, s), 6.17 (1H, t), 5.90 (2H, t), 3.65 (2H,m), 3.42-3.67 (2H, m), 3.31 (1H, m), 3.10-3.20 (3H, m), 2.14 (1H, m),1.64 (2H, m), 1.36-1.50 (3H, m), 1.30 (2H, m), 1.22 (1H, m), 0.88 (3H,t).

Example 106-Amino-2-butoxy-9-(tetrahydrofuran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one

2-Butoxy-8-methoxy-9-(tetrahydrofuran-3-ylmethyl)-9H-purin-6-amine (97mg) was dissolved in methanol (2 mL) and treated with 4N hydrogenchloride in 1,4-dioxane (1 mL). The reaction mixture was stirred for 4hours. The reaction was stripped to dryness. Water (2 mL) and methanol(15 mL) was added to the residue and then neutralised by the addition of2N sodium hydroxide solution. The above was stripped to near dryness(small quantity of water remaining) and the solid thus obtained wasfiltered (transferred and washed the solid with water (2 mL, 3 times)).The solid was dried under suction before being dried further in vacuo(50° C.) for 2 hours. This afforded the title compound as a white solid(62 mg).

MS calcd for (C₁₄H₂₁N₅O₃)⁺=307

MS found (electrospray): (M+H)⁺=308

1H NMR ((CD₃)₂SO): 9.88 (1H, s), 6.42 (2H, s), 4.13 (2H, t), 3.75 (1H,m), 3.65-3.56 (4H, overlapping m), 3.51 (1H, m), 2.68 (1H, m), 1.87 (1H,m), 1.66-1.57 (3H, overlapping m), 1.38 (2H, m), 0.90 (3H, t).

Example 116-Amino-2-butoxy-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one

2-Butoxy-8-methoxy-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-9H-purin-6-amine(0.11 g) was dissolved in methanol (2 mL) and treated with 4N hydrogenchloride in 1,4-dioxane (1 mL). The reaction mixture was stirred for 4hours and was stripped to dryness. Water (2 mL) and methanol (15 mL)were added to the residue and then neutralised by the addition of 2Nsodium hydroxide solution. The above was stripped to near dryness (smallquantity of water remaining) and the solid thus obtained was filtered(transferred and washed the solid with water (3 mL)). The solid wasdried under suction before being dried further in vacuo to afford thetitle compound as a white solid (82 mg).

MS calcd for (C₁₆H₂₅N₅O₃)⁺=335

MS found (electrospray): (M+H)⁺=336

1H NMR ((CD₃)₂SO): 9.84 (1H, s), 6.40 (2H, s), 4.13 (2H, t), 3.79 (2H,dd), 3.70 (2H, d), 3.21 (2H, t), 1.70-1.53 (6H, overlapping m),1.46-1.32 (3H, overlapping m), 1.14 (2H, m), 0.91 (3H, t).

Example 126-Amino-2-butoxy-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one

2-Butoxy-8-methoxy-9-(tetrahydro-2H-pyran-3-ylmethyl)-9H-purin-6-amine(105 mg) was dissolved in methanol (2 mL) and treated with 4N hydrogenchloride in 1,4-dioxane (1 mL). The reaction mixture was stirred for 4hours and stripped to dryness.

Water (2 mL) and methanol (15 mL) were added to the residue and thenneutralised by the addition of 2N sodium hydroxide solution. The abovewas stripped to near dryness (small volume of water remaining) and thesolid thus obtained was filtered off under suction (transferred andwashed with water (2 mL, 3 times)). The solid was dried under suctionbefore being dried further in vacuo to afford the title compound as awhite solid (71.5 mg).

MS calcd for (C₁₅H₂₃N₅O₃)⁺=321

MS found (electrospray): (M+H)⁺=322

1H NMR ((CD₃)₂SO): 9.85 (1H, s), 6.40 (2H, s), 4.13 (2H, t), 3.65 (2H,m), 3.54 (2H, m), 3.32 (1H, m), 3.15 (1H, dd), 2.02 (1H, m), 1.69-1.56(4H, overlapping m), 1.45-1.32 (3H, overlapping m), 1.21 (1H, m), 0.91(3H, t).

Example 136-Amino-2-butoxy-9-[2-(tetrahydrofuran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one

2-Butoxy-8-methoxy-9-[2-(tetrahydrofuran-2-yl)ethyl]-9H-purin-6-amine(122 mg) was dissolved in methanol (2 ml) and 4N hydrogen chloride indioxan (1 ml) added. After 4 h the reaction mixture was made basic with2N sodium hydroxide (2.2 ml) then the organic solvents stripped. A fewdrops of 2N hydrochloric acid were added and the pH adjusted back to 7-8with saturated sodium hydrogen carbonate. The resulting solid wasfiltered, washed and dried to give the title compound as a solid, yield65 mg.

MS calcd for (C₁₅H₂₃N₅O₃)⁺=321

MS found (electrospray): (M+H)⁺=322

¹H NMR ((CD₃)₂SO): δ 9.83 (1H, s), 6.39 (2H, s), 4.14 (2H, t), 3.72 (4H,m), 3.56 (1H, m), 1.96 (1H, m), 1.80 (4H, m), 1.64 (2H, m), 1.38 (3H,m), 1.91 (3H, t).

25 mg of this mixture of enantiomers was resolved by chiral HPLC on a2×25 cm Chiralpak AS column eluted with heptane:ethanol 7:3 with a flowrate of 15 mL/min over 30 min to provide Example 13 Isomer 1 (9.9 mg)and Example 13 Isomer 2 (10.8 mg).

Example 13 Isomer 1: Analytical chiral HPLC (25×0.46 cm Chiralpak AScolumn, heptane:ethanol 7:3 eluting at 1 mL/min, 30 min run):t_(RET)=10.8 min.

LCMS (Method A): t_(RET)=2.78 min; MH⁺=322

Example 13 Isomer 2: Analytical chiral HPLC (25×0.46 cm Chiralpak AScolumn, heptane:ethanol 7:3 eluting at 1 mL/min, 30 min run):t_(RET)=15.8 min.

LCMS (Method A): t_(RET)=2.78 min; MH⁺=322

Example 146-Amino-2-butylamino-9-[2-(tetrahydrofuran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one

N²-Butyl-8-methoxy-9-[2-(tetrahydrofuran-2-yl)ethyl]-9H-purine-2,6-diamine(107 mg) was dissolved in methanol (2 ml) and 4N hydrogen chloride indioxan (1 ml) added. After 4 h the solvents were stripped and theresidue taken up in water and basified with 2N sodium hydroxide. A fewdrops of 2N hydrochloric acid were added and the pH adjusted to 7-8 byaddition of saturated sodium hydrogen carbonate. The resulting solid wasfiltered, washed and dried to give the title compound as a solid, yield101 mg.

MS calcd for (C₁₅H₂₄N₆O₂)⁺=320

MS found (electrospray): (M+H)⁺=321

¹H NMR ((CD₃)₂SO): δ 9.51 (1H, s), 6.17 (1H, m), 5.94 (2H, s), 3.77-3.53(5H, m), 3.16 (2H, m), 1.96 (1H, m), 1.80 (4H, m), 1.51-1.24 (5H, m),0.88 (3H, t).

Example 156-Amino-2-butoxy-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one

2-Butoxy-8-methoxy-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-9H-purin-6-amine(108 mg) was dissolved in methanol (2 ml) and 4N hydrogen chloride indioxan (1 ml) added. After 16 h the reaction mixture was stripped,quenched with water then saturated sodium hydrogen carbonate added, whena solid precipitated. This was filtered, washed with water and dried.The solid was treated with hot methanol and was filtered after allowingto cool to yield 66 mg of the title compound.

MS calcd for (C₁₆H₂₅N₅O₃)⁺=335

MS found (electrospray): (M+H)⁺=336

¹H NMR ((CD₃)₂SO): δ 9.85 (1H, s), 6.40 (2H, br. s), 4.15 (2H, t), 3.79(1H, m), 3.68 (3H, m), 3.25 (1H, m), 2.99 (1H, m), 1.87 (1H, m), 1.64(2H, m), 1.58-1.34 (7H, m), 1.14 (1H, m), 0.91 (3H, t).

Example 166-Amino-2-butylamino-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one

N²-Butyl-8-methoxy-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-9H-purine-2,6-diamine(138 mg) was dissolved in methanol (2 ml) and 4N hydrogen chloride indioxan (1 ml) added. After 4 h the reaction mixture was stripped,quenched with water then made basic with saturated sodium hydrogencarbonate. The resulting solid was filtered, washed and dried to givethe title compound, yield 105 mg.

MS calcd for (C₁₆H₂₆N₆O₂)⁺=334

MS found (electrospray): (M+H)⁺=335

¹H NMR ((CD₃)₂SO): δ 9.52 (1H, s), 6.14 (1H, t), 5.94 (2H, br. s), 3.78(1H, m), 3.71 (1H, m), 3.62 (2H, m), 3.24 (1H, m), 3.16 (2H, m), 2.98(1H, m), 1.87 (1H, m), 1.57-1.36 (7H, m), 1.29 (2H, m), 1.12 (1H, m),0.88 (3H, t).

A sample of this mixture of enantiomers was resolved by chiral HPLC on a2×25 cm Chiralpak AS column eluted with heptane:ethanol 85:15 with aflow rate of 15 mL/min over 60 min to provide Example 16 Isomer 1 (7.6mg) and Example 16 Isomer 2 (7.5 mg).

Example 16 Isomer 1: Analytical chiral HPLC (25×0.46 cm Chiralpak AScolumn, heptane:ethanol 85:15 eluting at 1 mL/min, 40 min run):t_(RET)=24.2 min.

LCMS (Method A): t_(RET)=2.51 min; MH⁺=335

Example 16 Isomer 2: Analytical chiral HPLC (25×0.46 cm Chiralpak AScolumn, heptane:ethanol 85:15 eluting at 1 mL/min, 40 min run):t_(RET)=29.0 min.

LCMS (Method A): t_(RET)=2.51 min; MH⁺=335

Example 176-Amino-2-[(2,2-dimethylpentyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of2-[(2,2-dimethylpentyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(116 mg) in dry MeOH (14.5 mL) was added 4N HCl in 1,4-dioxane (2.48mL). The mixture was stirred at room temperature for 3 h. The reactionwas neutralised to pH 7 with 2M sodium hydroxide solution and wasconcentrated in vacuo to give and off-white solid. The solid wastriturated with water (30 mL) and was filtered under reduced pressure togive the title compound as an off-white solid (76 mg).

MS calcd for (C₁₈H₂₉N₅O₃)⁺=363

MS found (electrospray): (M+H)⁺=364

¹H NMR ((CD₃)₂SO): δ 9.86 (1H, s), 6.42 (2H, s), 3.87 (2H, s), 3.81 (2H,br. d), 3.60-3.52 (2H, m), 3.29-3.15 (2H, m), 2.10-1.96 (1H, m),1.50-1.40 (2H, m), 1.31-1.16 (6H, m), 0.96-0.81 (9H, m).

Example 186-Amino-2-(pentylamino)-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of8-methoxy-N²-pentyl-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine-2,6-diamine(140 mg) in dry MeOH (15.7 mL) was added 4N HCl in 1,4-dioxane (2.65mL). The reaction mixture was stirred at room temperature for 3 h andwas then neutralised with 2M sodium hydroxide solution. The mixture wasconcentrated in vacuo and the residue was taken up into water (20 mL).The mixture was filtered under reduced pressure to give the titlecompound (95 mg) as an off-white solid.

MS calcd for (C₁₆H₂₆N₆O₂)⁺=334

MS found (electrospray): (M+H)⁺=335

¹H NMR ((CD₃)₂SO): δ 9.55 (1H, s), 6.19 (1H, s), 5.96 (2H, s), 3.81 (2H,d), 3.50 (2H, d), 3.27-3.07 (4H, m), 2.10-1.96 (1H, m), 1.55-1.37 (4H,m), 1.35-1.13 (6H, m), 0.92-0.79 (3H, m).

Example 196-Amino-2-[(3-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of2-[(3-methylbutyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(52 mg) in dry MeOH (5.7 mL) was added 4N HCl in 1,4-dioxane (0.971 mL)and the reaction mixture was stirred at room temperature for 3 h. Thereaction was neutralised to pH7 with 2M sodium hydroxide solution andconcentrated in vacuo to give a white solid. The solid was washed withwater (20 mL) and was filtered under reduced pressure to give the titlecompound as an off-white solid (31 mg).

MS calcd for (C₁₆H₂₅N₅O₃)⁺=335

MS found (electrospray): (M+H)⁺=336

¹H NMR ((CD₃)₂SO): δ 9.86 (1H, s), 6.40 (2H, s), 4.18 (2H, t), 3.81 (2H,dd), 3.55 (2H, t), 3.22 (2H, t), 2.09-1.95 (1H, m), 1.78-1.64 (1H, m),1.61-1.51 (2H, m), 1.49-1.40 (2H, m), 1.29-1.15 (2H, m), 0.91 (6H, d).

Example 206-Amino-2-[(2-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of2-[(2-methylbutyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(41 mg) in dry MeOH (4.5 mL) was added 4N HCl in 1,4-dioxane (0.766 mL)and the reaction mixture was stirred at room temperature for 3 h. Thereaction was neutralised with 2M sodium hydroxide solution andconcentrated in vacuo. The resulting white residue was taken up in water(20 mL) and was filtered under reduced pressure to give the titlecompound as an off-white solid (20 mg).

MS calcd for (C₁₆H₂₅N₅O₃)⁺=335

MS found (electrospray): (M+H)⁺=336

¹H NMR ((CD₃)₂SO): δ 9.88 (1H, br), 6.41 (2H, s), 4.08-4.00 (1H, m),3.97-3.90 (1H, m), 3.85-3.76 (2H, m), 3.56 (2H, d), 3.22 (2H, t),2.10-1.95 (1H, m), 1.82-1.68 (1H, m), 1.50-1.39 (3H, m), 1.29-1.12 (3H,m), 0.97-0.84 (6H, m).

Example 216-Amino-2-[(1-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of2-[(1-methylbutyl)oxy]-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(92 mg) in dry MeOH (9.9 mL) was added 4N HCl in 1,4-dioxane (1.7 mL)and the reaction mixture was stirred at room temperature for 3 h. Thereaction was neutralised to pH7 with 2M sodium hydroxide solution andconcentrated in vacuo to give an off-white solid. The solid wastriturated with water (30 mL) and filtered under reduced pressure togive the title compound as an off-white solid (55 mg).

MS calcd for (C₁₆H₂₅N₅O₃)⁺=335

MS found (electrospray): (M+H)⁺=336

¹H NMR ((CD₃)₂SO): δ 9.84 (1H, s), 6.36 (2H, s), 5.04-4.94 (1H, m),3.86-3.76 (2H, m), 3.53 (2H, d), 3.21 (2H, t), 2.08-1.96 (1H, m),1.68-1.55 (1H, m), 1.53-1.14 (10H, m), 0.92-0.83 (3H, m).

Example 226-Amino-2-[(2-methylbutyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

A mixture of2-chloro-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(40 mg) in 2-methyl-1-butylamine (117 mg) was heated in a microwave at170° C. for 15 mins. The mixture was concentrated in vacuo to give agreen oily residue which was purified by C₁₈ reverse phasechromatography (ISCO) using water (0.1% formic acid)-acetonitrile (0.05%formic acid) as eluent (20-60%) to give the title compound as anoff-white solid (9 mg).

MS calcd for (C₁₆H₂₆N₆O₂)⁺=334

MS found (electrospray): (M+H)⁺=335

¹H NMR ((CD₃)₂SO): δ 9.60 (1H, br), 6.18 (1H, t), 5.95 (2H, br),3.86-3.77 (2H, m), 3.50 (2H, d), 3.27-3.09 (3H, m), 3.00-2.89 (1H, m),2.11-1.98 (1H, m), 1.67-1.55 (1H, m), 1.49-1.33 (3H, m), 1.28-1.02 (3H,m), 0.91-0.80 (6H, m).

Example 236-amino-2-[(3-methylbutyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

A mixture of2-chloro-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(45 mg) in 3-methyl-1-butylamine (0.234 mL) was heated in a microwave at170° C. for 10 mins. The mixture was concentrated in vacuo to give agreen oily residue. This was purified by C₁₈ reverse phasechromatography (ISCO) using water (0.1% formic acid)-acetonitrile (0.05%formic acid) as eluent (20-60%) to give the title compound as a whitesolid (10 mg).

MS calcd for (C₁₆H₂₆N₆O₂)⁺=334

MS found (electrospray): (M+H)⁺=335

¹H NMR ((CD₃)₂SO): δ 9.61 (1H, s), 6.12 (1H, t), 5.97 (2H, s), 3.86-3.77(2H, m), 3.50 (2H, d), 3.27-3.14 (4H, m), 2.13-1.95 (1H, m), 1.68-1.12(7H, m), 0.96-0.79 (6H, m).

Example 246-Amino-2-[(1-methylbutyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of2-chloro-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(40 mg) in ethylene glycol (1.5 mL) was added 2-aminopentane (0.16 mL)and the mixture was heated in a microwave at 170° C. for 2×30 mins. Afurther portion of 2-aminopentane (0.08 mL) was added and the reactionwas heated in a microwave at 180° C. for 30 mins. The mixture was takenup in EtOAc (15 mL) and was washed with water (3×15 mL). The organicswere separated, dried over MgSO₄, filtered and concentrated in vacuo togive a brown residue. This was taken up in DCM and concentrated in avacuum oven to give the title compound as a brown solid (18 mg).

MS calcd for (C₁₆H₂₆N₆O₂)⁺=334

MS found (electrospray): (M+H)⁺=335

¹H NMR ((CD₃)₂SO): δ 9.56 (1H, br), 5.93 (2H, s), 5.88 (1H, d),3.85-3.76 (2H, m), 3.50 (2H, d), 3.26-3.14 (2H, m), 2.09-1.97 (1H, m),1.54-1.12 (9H, m), 1.05 (3H, d), 0.91-0.82 (3H, m).

Example 256-Amino-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of2-[(2-cyclopropylethyl)oxy]-8-methoxy-9-(tetrahydro-3-furanylmethyl)-9H-purin-6-amine(103.8 mg) in methanol (5 mL) was added 4N HCl in 1,4-dioxane (2 mL) andthe reaction mixture was stirred at room temperature for 4 h. Thereaction was evaporated under reduced pressure to give a gum. Water (3mL) was added to give a white solid. The mixture was adjusted to pH 7 byadding 2N sodium hydroxide solution and the white solid was filtered offunder suction, then washed with a few drops of MeOH. The material wasair dried under suction, then in a vacuum oven (50° C.) to give thetitle compound as white solid (77 mg).

MS calcd for (C₁₅H₂₁N₅O₃)⁺=319

MS found (electrospray): (M+H)⁺=320

¹H NMR ((CD₃)₂SO): δ 9.89 (1H, s), 6.44 (2H, s), 4.19 (2H t), 3.80-3.72(1H, m), 3.69-3.56 (4H, m), 3.55-3.49 (1H, m), 2.75-2.63 (1H, m),1.94-1.82 (1H, m), 1.68-1.53 (3H, m), 0.83-0.72 (1H, m), 0.47-0.37 (2H,m), 0.13-0.06 (2H, m).

Example 266-Amino-2-butyloxy-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one

A solution of2-butyloxy-8-methoxy-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-9H-purin-6-amine(88 mg) in methanol (2 mL) was treated with 4N HCl in 1,4-dioxane (1 mL)for 1 h. The reaction was evaporated and the residue treated with waterthen basified with saturated sodium bicarbonate solution. The resultingwhite solid was filtered, washed with water and dried to give the titlecompound (78.1 mg).

MS calcd for (C₁₆H₂₅N₅O₃)⁺=335

MS found (electrospray): (M+H)⁺=336

¹H NMR ((CD₃)₂SO): δ 9.80 (1H, s), 6.37 (2H, s), 4.14 (2H, t), 3.87-3.62(3H, m), 3.30-3.16 (2H, m), 1.80-1.50 (6H, m), 1.48-1.31 (5H, m),1.23-1.10 (1H, m), 0.91 (3H, t).

24 mg of this mixture of enantiomers was resolved by chiral HPLC on a2×25 cm Chiralpak AD column eluted with heptane:ethanol 90:10 with aflow rate of 15 mL/min over 40 min to provide Example 26 Isomer 1 (12.2mg) and Example 26 Isomer 2 (9.4 mg).

Example 26 Isomer 1: Analytical chiral HPLC (25×0.46 cm Chiralpak ADcolumn, heptane:ethanol 90:10 eluting at 1 mL/min, 30 min run):t_(RET)=12.3 min.

LCMS (Method A): t_(RET)=2.97 min; MH⁺=336

Example 26 Isomer 2: Analytical chiral HPLC (25×0.46 cm Chiralpak ADcolumn, heptane:ethanol 90:10 eluting at 1 mL/min, 30 min run):t_(RET)=15.4 min.

LCMS (Method A): t_(RET)=2.97 min; MH⁺=336

Example 276-Amino-2-butyloxy-9-[(2,2-dimethyltetrahydro-2H-pyran-4-yl)methyl]-7,9-dihydro-8H-purin-8-one

A solution of2-butyloxy-9-[(2,2-dimethyltetrahydro-2H-pyran-4-yl)methyl]-8-methoxy-9H-purin-6-amine(161 mg) in methanol (1 mL) was treated with 4N HCl in 1,4-dioxane (0.5mL) for 1 h. The reaction was evaporated and the residue treated withwater then basified with saturated sodium bicarbonate solution. Theresulting solid was filtered, washed with water and dried to give thetitle compound (122 mg).

MS calcd for (C₁₇H₂₇N₅O₃)⁺=349

MS found (electrospray): (M+H)⁺=350

¹H NMR ((CD₃)₂SO): δ 9.85 (1H, s), 6.40 (2H, s), 4.21-4.10 (2H, m),3.62-3.42 (4H, m), 2.27-2.14 (1H, m), 1.69-1.59 (2H, m), 1.46-1.33 (4H,m), 1.14-0.98 (8H, m), 0.95-0.88 (3H, m).

A sample of this mixture of enantiomers was resolved by chiral HPLC on a2×25 cm Chiralpak AS column eluted with heptane:ethanol 95:5 with a flowrate of 15 mL/min over 60 min to provide Example 27 Isomer 1 (9.07 mg)and Example 27 Isomer 2 (7.7 mg).

Example 27 Isomer 1: Analytical chiral HPLC (25×0.46 cm Chiralpak AScolumn, heptane:ethanol 95:5 eluting at 1 mL/min, 40 min run):t_(RET)=18.6 min.

LCMS (Method A): t_(RET)=2.81 min; MH⁺=350

Example 27 Isomer 2: Analytical chiral HPLC (25×0.46 cm Chiralpak AScolumn, heptane:ethanol 95:5 eluting at 1 mL/min, 40 min run):t_(RET)=23.5 min.

LCMS (Method A): t_(RET)=2.81 min; MH⁺=350

Example 286-Amino-2-(butylamino)-9-[(2,2-dimethyltetrahydro-2H-pyran-4-yl)methyl]-7,9-dihydro-8H-purin-8-one

A solution ofN²-butyl-9-[(2,2-dimethyltetrahydro-2H-pyran-4-yl)methyl]-8-methoxy-9H-purine-2,6-diamine(73 mg) in MeOH (2 mL) was treated with 4N HCl in 1,4-dioxane (1 mL) andwas stirred for 4 h. The reaction was evaporated and the residue treatedwith water then basified with saturated sodium bicarbonate solution. Theresulting solid was filtered, washed with water and dried. The solid wasre-precipitated from ether/light petrol to give the title compound (37mg).

MS calcd for (C₁₇H₂₈N₆O₂)⁺=348

MS found (electrospray): (M+H)⁺=349

¹H NMR ((CD₃)₂SO): δ 9.54 (1H, s), 6.17 (1H, br.t), 5.95 (2H, br),3.62-3.54 (1H, m), 3.52-3.39 (3H, m), 3.23-3.12 (2H, m), 2.29-2.14 (1H,m), 1.52-1.37 (4H, m), 1.36-1.23 (2H, m), 1.14-0.95 (8H, m), 0.92-0.83(3H, m).

Example 296-Amino-2-butyloxy-9-[2-(tetrahydro-3-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one

A solution of2-butyloxy-8-methoxy-9-[2-(tetrahydro-3-furanyl)ethyl]-9H-purin-6-amine(102 mg) in methanol (1 mL) was treated with 4N HCl in 1,4-dioxane (0.5mL) for 1.5 h. The reaction was evaporated and the residue treated withwater then basified with saturated sodium bicarbonate solution. Theresulting solid was filtered, washed with water and dried to give thetitle compound (65 mg).

MS calcd for (C₁₅H₂₃N₅O₃)⁺=321

MS found (electrospray): (M+H)⁺=322

¹H NMR ((CD₃)₂SO): δ 9.86 (1H, s), 6.41 (2H, s), 4.19-4.09 (2H, m),3.83-3.53 (5H, m), 3.25-3.17 (1H, m), 2.12-1.94 (2H, m), 1.77-1.58 (4H,m), 1.51-1.31 (3H, m), 0.91 (3H, t).

Example 306-Amino-2-(butylamino)-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one

A solution ofN²-butyl-8-(methoxy)-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-9H-purine-2,6-diamine(54 mg) in methanol (1 ml) was treated with 4N HCl in dioxin (0.5 ml)and stood for 1.5 h. The solvents were stripped and the residue treatedwith water and made basic with saturated aqueous sodium bicarbonate. Theprecipitated material was filtered, washed with water and dried to givethe title compound as a solid, yield 22.5 mg.

MS calcd for (C₁₆H₂₆N₆O₂)⁺=334

MS found (electrospray): (M+H)⁺=335

¹H NMR ((CD₃)₂SO): δ 9.49 (1H, s), 6.14 (1H, m), 5.93 (2H, m), 3.83 (1H,m), 3.78-3.58 (2H, m), 3.34-3.12 (4H, m), 1.79-1.10 (12H, m), 0.87 (3H,t).

Example 316-Amino-2-(butylamino)-9-[2-(tetrahydro-3-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one

A solution ofN²-butyl-8-(methoxy)-9-[2-(tetrahydro-3-furanyl)ethyl]-9H-purine-2,6-diamine(181 mg) in methanol (1 mL) was treated with 4N HCl in 1,4-dioxane (0.5mL) for 1.5 h. The reaction was evaporated and the residue treated withwater then basified with saturated sodium bicarbonate solution. Theresulting solid was filtered, washed with water and dried to give thetitle compound (111 mg).

MS calcd for (C₁₅H₂₄N₆O₂)⁺=320

MS found (electrospray): (M+H)⁺=321

¹H NMR ((CD₃)₂SO): δ 9.54 (1H, s), 6.17 (1H, br.t), 5.97 (2H, s), 3.79(1H, m), 3.74-3.54 (4H, m), 3.18 (3H, m), 2.02 (2H, m), 1.70 (2H, m),1.45 (3H, m), 1.28 (2H, m), 0.87 (3H, t).

Example 326-Amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,Isomer 1

Example 32 (Isomer 1):2-Butoxy-8-methoxy-9-(tetrahydrofuran-3-ylmethyl)-9H-purin-6-amine(isomer 1, 176 mg) was suspended in methanol (2 ml) and 4N HCl in dioxan(1 ml) added. The resulting clear solution was stripped and the residuetreated with water and basified with saturated aqueous sodiumbicarbonate. The solid obtained was filtered, washed with water anddried to give the title compound yield 145 mg.

MS calcd for (C₁₄H₂₁N₅O₃)⁺=307

MS found (electrospray): (M+H)⁺=308

1H NMR ((CD₃)₂SO): 9.88 (1H, s), 6.43 (2H, s), 4.14 (2H, t), 3.76 (1H,m), 3.68-3.57 (4H, m), 3.52 (1H, m), 2.69 (1H, m), 1.88 (1H, m), 1.64(3H, m), 1.38 (2H, m), 0.92 (3H, t).

Example 32, Alternative Procedure6-Amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one(Isomer 1)

2-(Butyloxy)-8-(methoxy)-9-(tetrahydro-3-furanylmethyl)-9H-purin-6-amine(Isomer 1, 1.54 gm) was suspended in methanol (20 ml) and 4N HCl indioxan (4 ml) added with stirring to give a clear solution. After 6.5 h,the solvents were evaporated to low volume and water added withstirring, followed by neutralisation with saturated sodium bicarbonate.The resulting off-white solid was filtered, washed with water and dried,yield 1.26 gm. This material was added portionwise to boiling methanol(130 ml), adding a further 20 ml of methanol. The suspension wasfiltered, and the solid treated with boiling methanol (20 ml) and addedto the filtrate. This was reboiled, then allowed to cool with stirringwhen a white solid crystallised out. This was filtered, washed withmethanol and dried, to give the title compound yield 932 mg.

MS calcd for (C₁₄H₂₁N₅O₃)⁺=307

MS found (electrospray): (M+H)⁺=308

¹H NMR ((CD₃)₂SO): δ 9.89 (1H, s), 6.43 (2H, s), 4.14 (2H, m), 3.81-3.72(1H, m), 3.70-3.55 (4H, m), 3.55-3.48 (1H, m), 2.75-2.64 (1H, m),1.94-1.83 (1H, m), 1.70-1.58 (3H, m), 1.45-1.33 (2H, m), 0.96-0.88 (3H,q).

Example 336-Amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,Isomer 2

2-Butoxy-8-methoxy-9-(tetrahydrofuran-3-ylmethyl)-9H-purin-6-amine(Isomer 2, 178 mg) was suspended in methanol (2 ml) and 4N HCl in dioxan(1 ml) added. The resulting clear solution was stripped and the residuetreated with water and basified with saturated aqueous sodiumbicarbonate. The solid obtained was filtered, washed with water anddried to give the title compound (isomer 2), yield 72 mg (low due tomechanical losses).

MS calcd for (C₁₄H₂₁N₅O₃)⁺=307

MS found (electrospray): (M+H)⁺=308

1H NMR ((CD₃)₂SO): 9.88 (1H, s), 6.42 (2H, s), 4.15 (2H, t), 3.76 (1H,m), 3.68-3.57 (4H, m), 3.52 (1H, m), 2.69 (1H, m), 1.88 (1H, m), 1.64(3H, m), 1.38 (2H, m), 0.92 (3H, t).

Example 33, Alternative Procedure6-Amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one(Isomer 2)

2-(Butyloxy)-8-(methoxy)-9-(tetrahydro-3-furanylmethyl)-9H-purin-6-amine(Isomer 2, 1.96 gm) was suspended in methanol (20 ml) and 4N HCl indioxan (10 ml) added with stirring to give a clear solution. After 1.5h, the solvents were evaporated to low volume and water added withstirring, followed by neutralisation with saturated sodium bicarbonate.The resulting off-white solid was filtered, washed with water and dried,yield 1.73 gm. Initial attempts to recrystallise from methanol orethanol were unsuccessful. The recovered material was dissolved inglacial acetic acid (10 ml) with heating but precipitated immediately onaddition of water (10 ml). Further addition of acetic acid (4 ml) andheating gave a clear solution, from which the product crystallised onallowing to cool. The solid was filtered, washed and dried, yield 1.06gm (Crop 1). A second crop was obtained from the filtrate on standing,yield 460 mg, which was dissolved in sodium hydroxide and precipitatedby the addition of acetic acid and then the recovered solid was heatedin methanol (20 ml) with further additions of methanol (15 ml) to theboiling mixture to give a cloudy solution, which was allowed to cool.The resulting solid was filtered off, yield 257 mg. This was combinedwith the first batch of solid (Crop 1) and added portionwise to boilingmethanol (130 ml) to give a slightly cloudy solution. On allowing tocool with stirring, a white solid crystallised out which was filteredoff, washed with methanol and dried, to give the title compound yield1.02 gm.

MS calcd for (C₁₄H₂₁N₅O₃)⁺=307

MS found (electrospray): (M+H)⁺=308

¹H NMR ((CD₃)₂SO): δ 9.89 (1H, s), 6.43 (2H, s), 4.15 (2H, m), 3.81-3.72(1H, m), 3.70-3.55 (4H, m), 3.55-3.48 (1H, m), 2.75-2.64 (1H, m),1.94-1.83 (1H, m), 1.70-1.58 (3H, m), 1.45-1.33 (2H, m), 0.96-0.88 (3H,q).

Example 346-Amino-2-{[2-(ethyloxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of2-(2-ethoxyethoxy)-8-methoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(240 mg) in dry methanol (10 ml) at room temperature and under nitrogenwas added 4.0M hydrogen chloride in 1,4-dioxane (4.0 ml). The reactionwas left to stir at room temperature for 3 hours. The reaction wasneutralised by the addition of 2.0M sodium hydroxide solution andconcentrated in vacuo. The residue was taken up in water (15 ml) and thesolid filtered and washed with water (2×5 ml). The solid was dried envacuo (60° C.) for 30 minutes. This afforded the title compound as anoff-white solid (129 mg).

MS calcd for (C₁₅H₂₃N₅O₄)⁺=337

MS found (electrospray): (M+H)⁺=338

¹H NMR ((CD₃)₂SO): δ 9.92 (1H, s), 6.44 (2H, s), 4.25 (2H, s), 3.81 (2H,m), 3.63 (2H, m), 3.55 (2H, d), 3.47 (2H, q), 3.22 (2H, m), 2.03 (1H,m), 1.45 (2H, m), 1.22 (2H, m), 1.12 (3H, t).

Example 356-Amino-2-{[1-methyl-2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of2-{[1-methyl-2-(methoxy)ethyl]oxy}-8-(methoxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(260 mg) in dry methanol (10 ml) at room temperature and under nitrogenwas added 4.0M hydrogen chloride in 1,4-dioxane (4.0 ml). The reactionwas left to stir at room temperature for 3 hours. The reaction wasneutralised by the addition of 2.0M sodium hydroxide solution andconcentrated in vacuo. The residue was taken up in water (15 ml) and thesolid filtered and washed with water (2×5 ml). The solid was dried envacuo (60° C.) for 30 minutes. This afforded the title compound as anoff-white solid (70 mg).

MS calcd for (C₁₅H₂₃N₅O₄)⁺=337

MS found (electrospray): (M+H)⁺=338

¹H NMR ((CD₃)₂SO): δ 9.89 (1H, s), 6.41 (2H, br. s), 5.13 (1H, m), 3.81(2H, m), 3.55 (2H, d), 3.43 (2H, m), 3.27 (3H, s), 3.22 (2H, m), 2.02(1H, m), 1.46 (2H, m), 1.24 (2H, m), 1.21 (3H, d).

Example 366-Amino-2-{[2-(ethyloxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of2-(2-ethoxyethoxy)-8-methoxy-9-(tetrahydro-2H-pyran-3-ylmethyl)-9H-purin-6-amine(245 mg) in dry methanol (10 ml) at room temperature and under nitrogenwas added 4.0M hydrogen chloride in 1,4-dioxane (4.0 ml). The reactionwas left to stir at room temperature for 1 hour. The reaction wasconcentrated in vacuo and the resulting residue purified by C₁₈ reversephase chromatography using water (containing 0.1% formicacid)-acetonitrile (containing 0.05% formic acid) as eluant (10-45%) toafford a white solid. This was taken up in water (15 ml) and neutralisedby the addition of 2.0M sodium hydroxide solution. The solid wasfiltered and dried on the rotary evaporator (60° C.) for 30 minutes (90mg).

MS calcd for (C₁₅H₂₃N₅O₄)⁺=337

MS found (electrospray): (M+H)⁺=338

¹H NMR ((CD₃)₂SO): δ 9.90 (1H, s), 6.45 (2H, s), 4.25 (2H, m), 3.70-3.61(5H, m), 3.55 (1H, m), 3.47 (2H, q), 3.30 (1H, m), 3.16 (1H, m), 2.03(1H, m), 1.64 (2H, m), 1.40 (1H, m), 1.22 (1H, m), 1.11 (3H, t).

Example 376-Amino-2-{[1-methyl-2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of2-{[1-methyl-2-(methoxy)ethyl]oxy}-8-(methyloxy)-9-(tetrahydro-2H-pyran-3-ylmethyl)-9H-purin-6-amine(290 mg) in dry methanol (12 ml) at room temperature and under nitrogenwas added 4.0M hydrogen chloride in 1,4-dioxane (5.0 ml). The reactionwas left to stir at room temperature for 1 hour. The reaction wasconcentrated in vacuo and the resulting residue purified by C₁₈ reversephase chromatography using water (containing 0.1% formicacid)-acetonitrile (containing 0.05% formic acid) as eluant (10-45%) toafford a white solid. This was taken up in water (15 ml) and neutralisedby the addition of 2.0M sodium hydroxide solution. The solid wasfiltered and dried on the rotary evaporator (60° C.) for 30 minutes (50mg).

MS calcd for (C₁₅H₂₃N₅O₄)⁺=337

MS found (electrospray): (M+H)⁺=338

¹H NMR ((CD₃)₂SO): δ 9.90 (1H, s), 6.43 (2H, s), 5.12 (1H, m), 3.66 (2H,m), 3.55 (2H, m), 3.47 (1H, m), 3.38 (1H, m), 3.30 (1H, m), 3.27 (3H,s), 3.16 (1H, m), 2.02 (1H, m), 1.63 (2H, m), 1.40 (1H, m), 1.23 (1H,m), 1.20 (3H, t).

Example 386-Amino-2-[(cyclohexylmethyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of8-bromo-N²-(cyclohexylmethyl)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine-2,6-diamine(110 mg) in dry n-butanol (1.5 ml) was added 37% grade hydrochloric acid(1.5 ml) at RT. The reaction was heated to 100° C. for six hours. Thereaction was concentrated in vacuo, taken up in water (5 ml) andneutralised by the addition of 2.0M sodium hydroxide solution. Theresulting white precipitate was filtered. This was purified by C₁₈reverse phase chromatography using water (containing 0.1% formicacid)-acetonitrile (containing 0.05% formic acid) as eluant (20-60%) toafford a white solid (20 mg).

MS calcd for (C₁₈H₂₈N₆O₂)⁺=360

MS found (electrospray): (M+H)⁺=361

¹H NMR ((CD₃)₂SO): δ 9.59 (1H, s), 6.21 (1H, s), 5.97 (2H, s), 3.81 (2H,m), 3.51 (2H, d), 3.21 (2H, m), 3.01 (2H, m), 2.04 (1H, m), 1.74-1.54(5H, m), 1.52 (1H, m), 1.44 (2H, m), 1.28-1.04 (5H, m), 0.84 (2H, m).

Example 396-Amino-2-[(cyclopentylmethyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of8-bromo-N²-(cyclopentylmethyl)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purine-2,6-diamine(40 mg) in dry n-butanol (0.5 ml) was added 37% grade hydrochloric acid(1.5 ml) in one go and at RT. The reaction was heated to 100° C. forthirty minutes. The reaction was concentrated in vacuo and the productwas purified by C₁₈ reverse phase chromatography using water (containing0.1% formic acid)-acetonitrile (containing 0.05% formic acid) as eluant(20-60%) to afford the title compound as a white solid (10 mg).

MS calcd for (C₁₇H₂₆N₆O₂)⁺=346

MS found (electrospray): (M+H)⁺=347

¹H NMR ((CD₃)₂SO): δ 9.55 (1H, s), 6.19 (1H, s), 5.95 (2H, s), 3.81 (2H,m), 3.50 (2H, d), 3.21 (2H, m), 3.10 (2H, t), 2.13 (1H, m), 2.04 (1H,m), 1.69-1.59 (2H, m), 1.59-1.50 (2H, m), 1.50-1.40 (4H, m), 1.21 (4H,m).

Example 406-Amino-2-[(2-cyclopropylethyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of 2-chloro-9-(tetrahydro-2H-pyran-2-yl)-9H-purin-6-amine(550 mg) in dry ethylene glycol (27 ml) at room temperature was added2-cyclopropylethylamine (740 mg). The reaction was heated at 120° C.overnight. The reaction was cooled to RT, diluted with ethyl acetate (70ml) and washed with water (3×20 ml). The organic layer was dried overMgSO₄, filtered and concentrated in vacuo. This afford a brown viscousoil (580 mg) that was used in the next step without furtherpurification. To a solution of this oil (580 mg) in dry chloroform (6.5ml) at RT was added NBS (320 mg) and the reaction was stirred for 15minutes. The reaction was diluted with DCM (20 ml) and washed with water(10 ml). The organics were passed through a hydrophobic frit andconcentrated in vacuo. This afforded a light brown oil which wasdissolved in dry methanol (5 ml) and at room temperature was addedsodium methoxide solution (25 wt. % in methanol, 1.3 ml). The reactionwas heated at 60° C., with a condenser attached, overnight. The reactionwas cooled and concentrated in vacuo. The resultant orange residue wastaken up in ethyl acetate (30 ml) and washed with saturated aqueousammonium chloride (20 ml). The organic layer was separated and washedfurther with water (2×15 ml). The organic layer was dried over MgSO₄,filtered and concentrated in vacuo. To this material in dry methanol(3.5 ml) at RT was added trifluoroacetic acid (0.35 ml) in one go. Thereaction was stirred at RT for 16 hours and concentrated in vacuo. Thiswas taken up in diethyl ether and triturated to afford a brown solid(227 mg). To a solution of this solid (160 mg) in dryN,N-dimethylformamide (1.5 ml) at room temperature and under nitrogenwas added potassium carbonate (240 mg). The reaction was stirred at 60°C. for 1.5 hours and then cooled to 50° C.4-(bromomethyl)tetrahydro-2H-pyran (59 ul) was added and the reactionheated at 50° C. overnight. An additional amount of4-(bromomethyl)tetrahydro-2H-pyran (29 ul) was added and the reactionheated at 70° C. for 8 hours. The reaction was cooled to RT and dilutedwith ethyl acetate (20 ml) and washed with water (5 ml). The organiclayer was dried over MgSO₄, filtered and concentrated in vacuo to afforda brown oil. This was purified by C₁₈ reverse phase chromatography usingwater (containing 0.1% formic acid)-acetonitrile (containing 0.05%formic acid) as eluant (20-60%). The resulting clear viscous oil (50 mg)was dissolved in dry methanol (1.8 ml) at RT and under nitrogen. To thiswas added 4.0M hydrogen chloride in 1,4-dioxane (0.8 ml). The reactionwas left to stir at RT for 3 hours. The reaction was neutralised by theaddition of saturated NaHCO₃ solution and concentrated in vacuo. Thewhite residue was taken up in water (15 ml) and the solid filtered. Thesolid was dried en vacuo (60° C.) for 30 minutes. This afforded thetitle compound as a beige solid (33 mg).

MS calcd for (C₁₆H₂₄N₆O₂)⁺=332

MS found (electrospray): (M+H)⁺=333

¹H NMR ((CD₃)₂SO): δ 9.55 (1H, s), 6.16 (1H, s), 5.97 (2H, s), 3.81 (2H,m), 3.50 (2H, d), 3.21 (4H, m), 2.03 (1H, m), 1.40 (4H, m), 1.21 (2H,m), 0.69 (1H, m), 0.38 (2H, m), 0.03 (2H, m).

Example 41 and Example 42 Isomers of6-Amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one

The enantiomers of6-amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-onewere separated by chiral chromatography (Chiralpak AS) using heptane-IPA(containing 0.15% triethylamine) as eluant (20%). Thus racemic6-amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one(700 mg) afforded both enantiomers as yellow/orange liquids. These weretriturated with water (15 ml) to yield off white solids, which werefiltered and dried on a rotary evaporator (60° C.) for 15 minutes. Thisafforded Enantiomer 1 (163 mg) and Enantiomer 2 (145 mg) both containingsome triethylamine. These were further purified by C₁₈ reverse phasechromatography using water (containing 0.1% formic acid)-acetonitrile(containing 0.05% formic acid) as eluant (10-45%) to afford isomer 1 (40mg) as a white solid and isomer 2 (55 mg) as a white solid.

Example 41 (Isomer 1):

MS calcd for (C₁₄H₂₂N₆O₂)⁺=306

MS found (electrospray): (M+H)⁺=307

¹H NMR ((CD₃)₂SO): δ 9.67 (1H, s), 6.43 (1H, m), 6.21 (1H, m), 3.75 (2H,m), 3.61 (4H, m), 3.53 (1H, m), 3.18 (2H, m), 2.68 (1H, m), 1.86 (1H,m), 1.64 (1H, m), 1.47 (2H, m), 1.30 (2H, m), 0.88 (3H, t).

Example 42 (Isomer 2):

MS calcd for (C₁₄H₂₂N₆O₂)⁺=306

MS found (electrospray): (M+H)⁺=307

¹H NMR ((CD₃)₂SO): δ 9.69 (1H, s), 6.44 (1H, m), 6.22 (1H, m), 3.75 (2H,m), 3.61 (4H, m), 3.52 (1H, m), 3.18 (2H, m), 2.68 (1H, m), 1.86 (1H,m), 1.64 (1H, m), 1.47 (2H, m), 1.30 (2H, m), 0.88 (3H, t).

Example 41 Alternative Method6-Amino-2-(butylamino)-9-[tetrahydro-3-furanylmethyl]-7,9-dihydro-8H-purin-8-one,Isomer 1

To a solution ofN²-butyl-8-(methoxy)-9-[tetrahydro-3-furanylmethyl]-9H-purine-2,6-diamine,Isomer 1 (2.79 g) in dry methanol (100 ml) at room temperature and undernitrogen was added 4.0M hydrochloric acid in 1,4-dioxane (28 ml). Thereaction was left to stir at room temperature for 2 hours. The reactionwas neutralised by the addition of 2.0M sodium hydroxide solution andconcentrated in vacuo to yield an off white residue. The residue wastaken up in water (30 ml) and the solid filtered and washed with water(15 ml). The beige solid was dried on a rotary evaporator (60° C.) for30 minutes. This was crystallised from water/ethanol (1:1, 35 ml) toyield a white solid (1.3 g). This was only partially crystalline.Recrystallisation of this compound with water/ethanol (1:1, 80 ml)afforded an off-white solid which was dried on the rotary evaporator(60° C.) for 1 hour (1.2 g, 100% e.e.).

MS calcd for (C₁₄H₂₂N₆O₂)⁺=306

MS found (electrospray): (M+H)⁺=307

¹H NMR ((CD₃)₂SO): δ 9.57 (1H, s), 6.18 (1H, m), 5.97 (2H, m), 3.75 (1H,m), 3.64-3.56 (4H, m), 3.52 (1H, m), 3.16 (2H, m), 2.69 (1H, m), 1.86(1H, m), 1.64 (1H, m), 1.46 (2H, m), 1.29 (2H, m), 0.88 (3H, t).

Example 42 Alternative Method6-Amino-2-(butylamino)-9-[tetrahydro-3-furanylmethyl]-7,9-dihydro-8H-purin-8-one,Isomer 2

To a solution ofN²-butyl-8-(methoxy)-9-[tetrahydro-3-furanylmethyl]-9H-purine-2,6-diamine,Isomer 2 (3 g) in dry methanol (100 ml) at room temperature and undernitrogen was added 4.0M hydrochloric acid in 1,4-dioxane (30 ml). Thereaction was left to stir at room temperature for 2 hours. The reactionwas neutralised by the addition of 2.0M sodium hydroxide solution andconcentrated in vacuo to yield an off white residue. The residue wastaken up in water (30 ml) and the solid filtered and washed with water(15 ml). The beige solid was dried on a rotary evaporator (60° C.) for30 minutes. This was recrystallised from water/ethanol (1:1, 40 ml) toyield a white solid (1.5 g). This was only partially crystalline.Recrystallisation of this compound with water/ethanol (1:1, 80 ml)afforded an off-white solid which was dried on the rotary evaporator(60° C.) for 1 hour (1.3 g). This was only partially crystalline.Repeated recrystallisation of this compound with water/ethanol (1:1, 80ml) afforded an off-white solid which was dried on the rotary evaporator(60° C.) for 1 hour (1.3 g, 91% e.e.).

MS calcd for (C₁₄H₂₂N₆O₂)⁺=306

MS found (electrospray): (M+H)⁺=307

¹H NMR ((CD₃)₂SO): δ 9.57 (1H, s), 6.19 (1H, m), 5.97 (2H, m), 3.75 (1H,m), 3.67-3.48 (5H, m), 3.16 (2H, m), 2.68 (1H, m), 1.85 (1H, m), 1.64(1H, m), 1.46 (2H, m), 1.29 (2H, m), 0.87 (3H, t).

Example 436-Amino-2-[(2-methylpropyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

8-Bromo-2-[(2-methylpropyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(100 mg) in n-butanol (2 mL) was refluxed with concentrated hydrochloricacid (2 mL) at 100° C. (external temperature) for 3 hours. The reactionmixture was evaporated under reduced pressure to dryness. To thereaction mixture was then added a small volume of water and anequivalent volume of methanol to give a suspension, which was thenneutralised to by the addition of 2M sodium hydroxide (from pH ˜3 to 7).This was then evaporated under reduced pressure to give a beige solidwhich was purified by C₁₈ reverse phase chromatography using water(containing 0.1% formic acid)-acetonitrile (containing 0.05% formicacid) as eluent (20-60%). This gave the title compound (13 mg) as whitesolid.

1H NMR ((CD₃)₂SO): 9.95 (1H, s), 6.50 (2H, broad s), 3.96-3.92 (2H, m),3.85-3.78 (2H, m), 3.57-3.55 (2H, m, [overlapped by water]), 3.27-3.18(2H, m), 2.09-1.92 (2H, m), 1.50-1.42 (2H, m), 1.29-1.15 (2H, m),0.98-0.92 (6H, m).

MS calcd for (C₁₅H₂₃N₅O₃)⁺=321

MS found (electrospray): (M+H)⁺=322

Example 446-Amino-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

2-[(2-Cyclopropylethyl)oxy]-8-(methoxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(0.1259 g) was dissolved in methanol (5 mL) and added 4N hydrogenchloride in 1,4-dioxane (2 mL). The reaction was stirred at roomtemperature for 4 hours. The reaction mixture was evaporated underreduced pressure to give a solid which was then suspended in water (1mL) and small quantity of methanol (2-3 mL). This was then neutralised(to pH 7) by the addition of 2N sodium hydroxide. The suspension wasevaporated to near dryness under reduced pressure and then suspended thesolid in water (3 mL). The solid was filtered off under suction andwashed with a few drops of methanol before being air-dried undersuction. This material was then dried to constant weight under vacuo at50° C. to give the title compound (94 mg).

1H NMR ((CD₃)₂SO): 9.87 (1H, s), 6.42 (2H, s), 4.25-4.16 (2H, m),3.86-3.78 (2H, m), 3.59-3.53 (2H, m), 3.27-3.18 (2H, m) 2.09-1.96 (1H,m), 1.61-1.53 (2H, m) 1.50-1.41 (2H, m), 1.29-1.14 (2H, m), 0.82-0.72(1H, m), 0.45-0.39 (2H, m) 0.13-0.07 (2H, m).

LCMS HE101125-2

MS calcd for (C₁₆H₂₃N₅O₃)⁺=333

MS found (electrospray): (M+H)⁺=334

Example 456-Amino-2-[(cyclohexylmethyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

2-[(Cyclohexylmethyl)oxy]-8-(methoxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(RS105369-181A2) (0.1657 g) was dissolved in methanol (5 mL) and thenadded 4N hydrogen chloride in 1,4-dioxane (2 mL). The reaction mixturewas stirred at room temperature for 4 hours. The reaction mixture wasthen evaporated under reduced pressure to give a solid that was thensuspended in water (1 mL) and methanol (˜2-3 mL) before beingneutralised (to pH 7) by the addition of 2N sodium hydroxide. Theresultant mixture was evaporated to near dryness before being suspendedin water (3 mL) and the solid is filtered off under suction. This solidwas then washed with a few drops of methanol and then air-dried undersuction before finally being dried to constant weight under vacuo at 50°C. This gave the title compound as a white solid (134 mg).

1H NMR ((CD₃)₂SO): 9.86 (1H, s), 6.41 (2H, s), 3.99-3.93 (2H, m),3.85-3.78 (2H, m), 3.59-3.52 (2H, m), 3.27-3.18 (2H, m), 2.09-1.96 (1H,m), 1.79-1.60 (6H, overlapping m), 1.50-1.41 (2H, m), 1.29-1.09 (5H,overlapping m), 1.06-0.93 (2H, m).

MS calcd for (C₁₈H₂₇N₅O₃)⁺=361

MS found (electrospray): (M+H)⁺=362

Example 466-Amino-2-{[2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

8-(Methoxy)-2-{[2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(0.1434 g) was dissolved in methanol (5 mL) and treated with 4N hydrogenchloride in 1,4-dioxane (2 mL). The reaction mixture was stirred at roomtemperature for 4 hours. The reaction mixture was evaporated underreduced pressure to give a solid, which was suspended in water (1 mL)and methanol (2-3 mL) before 2N sodium hydroxide was added to neutralise(to pH 7). After evaporating the suspension to near dryness underreduced pressure, the solid was suspended in water (3 mL) and filteredunder suction and then washed with a few drops of methanol. This solidwas dried to constant weight under vacuo at 50° C. after being initiallyair-dried under suction. This gave the title compound as a white solid(94 mg).

1H NMR ((CD₃)₂SO): 9.89 (1H, s), 6.44 (2H, broad s), 4.30-4.22 (2H, m)3.86-3.77 (2H, m), 3.65-3.87 (4H, overlapping m), 3.29 (3H, s),3.27-3.17 (2H, m), 2.10-1.96 (1H, m), 1.50-1.40 (2H, m), 1.29-1.15 (2H,m).

MS calcd for (C₁₄H₂₁N₅O₄)⁺=323

MS found (electrospray): (M+H)⁺=324

Example 476-Amino-2-{[2-(methoxy)ethyl]oxy}-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one

8-(Methoxy)-2-{[2-(methoxy)ethyl]oxy}-9-(tetrahydro-3-furanylmethyl)-9H-purin-6-amine(0.1233 g) was dissolved in methanol (5 mL). To this solution was added4N hydrogen dioxane (2 mL), stirred at room temperature for 4 hours. Thereaction mixture was evaporated under reduced pressure to give a gum. Tothis material was added water (3 mL) to give a solution, which was thenneutralised (to pH 7) using 2N sodium hydroxide. This gave a white solidwhich was filtered under suction and then washed with a few drops ofmethanol. The solid was then air-dried under suction before being driedin under vacuo at 50° C. for 2 hours. This gave the title compound as awhite solid (86 mg).

1H NMR ((CD₃)₂SO): 9.92 (1H, s), 6.46 (2H, s), 4.29-4.23 (2H, m),3.80-3.72 (1H, m), 3.69-3.56 (6H, overlapping m), 3.55-3.48 (1H, m),3.28 (3H, s), 2.75-2.63 (1H, m), 1.94-1.83 (1H, m), 1.68-1.58 (1H, m).

MS calcd for (C₁₃H₁₉N₅O₄)⁺=309

MS found (electrospray): (M+H)⁺=310

Example 486-Amino-2-[(tetrahydro-2-furanylmethyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

8-(Methoxy)-2-[(tetrahydro-2-furanylmethyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(0.1500 g) was dissolved in methanol (10 mL). To this solution was added4N hydrogen chloride in 1,4-dioxane (2 mL). The reaction mixture wasstirred for 5 hours at room temperature. The reaction mixture wasevaporated under reduced pressure and then water (3 mL) and methanol (3mL) was added to the residue to give a finely divided suspension. Thiswas neutralised (to pH 7) by the addition of 2N sodium hydroxide andthen evaporated under reduced pressure to dryness. Water (3 mL) was thenadded to the residue and the resultant white suspension of solid wasisolated by filtration under suction. The solid was washed with methanol(1 mL) and then air-dried under suction. The solid was then driedfurther to constant weight under vacuo at 50° C. (˜1 hour). This gavethe title compound as a white solid (0.1130 g)

1H NMR ((CD₃)₂SO): 9.88 (1H, s), 6.44 (2H, s), 4.15-4.06 (3H,overlapping m+s), 3.86-3.73 (3H, overlapping m), 3.69-3.62 (1H, m),3.59-3.53 (2H, m), 3.28-3.15 (2H, m), 2.10-1.76 (4H, m), 1.67-1.56 (1H,m), 1.50-1.41 (2H, m), 1.29-1.16 (2H, m).

MS calcd for (C₁₆H₂₃N₃O₄)⁺=349

MS found (electrospray): (M+H)⁺=350

Example 496-Amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-onehydrochloride salt

To6-Amino-2-(propyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one(52.6 mg) was added an excess of 4N hydrogen chloride in 1,4-dioxane (1mL). The resultant solution was evaporated under reduced pressure (after5 minutes) to give a colourless gum containing some crystals. To thismaterial was added diethyl ether to triturate out the 1,4-dioxane,giving a free flowing solid on scratching. After evaporation to drynessunder reduced pressure for 2 hours (water bath at 50° C., minimum vacuo˜38 mbar) gave the title compound (61 mg) an off-white free flowingsolid.

1H NMR ((CD₃)₂SO): 10.37 (1H, s), 6.88 (1H, very broad s), 5.46(representing 1H, very broad s [appears that shifted water peak fromDMSO interfering]), 4.26-4.19 (2H, m), 3.80-3.72 (1H, m), 3.71-3.56 (4H,overlapping m), 3.54-3.48 (1H, m), 2.74-2.63 (1H, m), 1.94-1.84 (1H, m),1.71-1.59 (3H, overlapping m), 1.46-1.34 (2H, m), 0.96-0.88 (3H, m).

MS calcd for (C₁₄H₂₁N₃O₃)⁺=307

MS found (electrospray): (M+H)⁺=308

Elemental analysis Calculated (%) Found (%) Found Average (%) C 48.91 C48.60 48.46 C 48.53 H 6.45 H 6.29 6.30 H 6.30 N 20.37 N 19.90 19.77 N19.84 Cl 10.31 Cl 10.48 10.0* Cl 10.24 Sample weight <3 mg

Example 506-Amino-2-(butylamino)-9-[3-(tetrahydro-2H-pyran-3-yl)propyl]-7,9-dihydro-8H-purin-8-one

To a solution ofN²-butyl-8-(methoxy)-9-[3-(tetrahydro-2H-pyran-3-yl)propyl]-9H-purine-2,6-diamine(198 mg) in dry methanol (20.8 ml) was added 4.0M hydrochloric acid in1,4-dioxane (3.6 ml) in one go. The reaction was left to stir at roomtemperature for 4 hours. The reaction was neutralised by the addition of2.0M sodium hydroxide solution and concentrated in vacuo. to give anoff-white solid. To this solid was added water, triturated, and thesolid filtered under vacuum until dry. This afforded the title compoundas an off-white solid (151 mg).

MS calcd for (C₁₇H₂₈N₆O₂)⁺=348

MS found (electrospray): (M+H)⁺=349

¹H NMR (DMSO): δ 9.52 (1H, s), 6.15 (1H, s), 5.94 (2H, s), 3.71 (2H, m),3.58 (2H, m), 3.27-3.12 (3H, m), 2.91 (1H, m), 1.77 (1H, m), 1.69-1.55(2H, m), 1.54-1.39 (5H, m), 1.35-1.22 (2H, m), 1.16-0.99 (3H, m), 0.88(3H, m).

Example 516-Amino-9-(tetrahydro-2H-pyran-4-ylmethyl)-2-[(tetrahydro-2H-pyran-2-ylmethoxy]-7,9-dihydro-8H-purin-8-one

To a solution of8-(methoxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-2-[(tetrahydro-2H-pyran-2-ylmethoxy]-9H-purin-6-amine(704 mg) in dry methanol (71 ml) was added 4.0M hydrogen chloride in1,4-dioxane (12.2 ml). The reaction was left to stir at room temperaturefor 6 hours. The reaction was neutralised by the addition of 2.0M sodiumhydroxide solution and concentrated in vacuo to give an off-whiteresidue. The residue was triturated in water, and the solid filtered togive a brown solid (588 mg). The product was purified by C₁₈ reversephase chromatography using water (containing 0.1% formicacid)-acetonitrile (containing 0.05% formic acid) as eluant (10-45%) toafford the title compound as a white solid (145 mg).

MS calcd for (C₁₇H₂₅N₅O₄)⁺=363

MS found (electrospray): (M+H)⁺=364

¹H NMR ((CD3)2SO): δ 9.88 (1H, s), 6.43 (2H, s), 4.07 (2H, d), 3.87 (1H,m), 3.81 (2H, m), 3.57 (1H, m), 3.55 (2H, d), 3.36 (1H, m), 3.22 (2H,m), 2.02 (1H, m), 1.79 (1H, m), 1.60 (1H, m), 1.51-1.41 (5H, m),1.31-1.15 (3H, m).

Example 526-Amino-2-({2-[(1-methylethyl)oxy]ethyl}oxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution of2-({2-[(1-methylethyl)oxy]ethyl}oxy)-8-(methoxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-9H-purin-6-amine(165 mg) in dry methanol (17 ml) was added 4.0M hydrogen chloride in1,4-dioxane (2.95 ml) in one go. The reaction was left to stir at roomtemperature for 5 hours. The reaction was neutralised by the addition of2.0M sodium hydroxide solution and concentrated in vacuo to give anoff-white solid. The solid was triturated in water, and filtered undervacuum, washing with more water, to give an off-white solid (120 mg).

MS calcd for (C₁₆H₂₅N₅O₄)⁺=351

MS found (electrospray): (M+H)⁺=352

¹H NMR ((CD3)2SO): δ 9.88 (1H, s), 6.43 (2H, s), 4.22 (2H, m), 3.81 (2H,m), 3.68-3.50 (5H, m), 3.22 (2H, m), 2.03 (1H, m), 1.45 (2H, m), 1.22(2H, m), 1.09 (6H, d).

Example 536-Amino-2-(butylamino)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one

To a solution ofN²-butyl-8-(methoxy)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-9H-purine-2,6-diamine(172 mg) in methanol (15.2 ml) at room temperature was added 4.0Mhydrogen chloride in 1,4-dioxane (2.86 ml, 11.42 mmol) to give acolourless solution. The reaction mixture was stirred at roomtemperature for 5 hours. The reaction mixture was neutralised with 2MNaOH and concentrated in vacuo to give a white solid. This solid wastriturated in water and filtered under vacuum to give an off-white solid(85 mg).

MS calcd for (C₁₈H₃₀N₆O₂)⁺=362

MS found (electrospray): (M+H)⁺=363

¹H NMR ((CD3)2SO): δ 9.51 (1H, s), 6.14 (1H, m), 5.94 (2H, s), 3.70 (2H,m), 3.59 (2H, m), 3.26-3.11 (3H, m), 2.90 (1H, m), 1.74 (1H, m), 1.60(2H, m), 1.54-1.35 (5H, m), 1.35-0.96 (7H, m), 0.88 (3H, t).

Example 546-Amino-2-[(2-cyclopropylethyl)amino]-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution ofN²-(2-cyclopropylethyl)-8-(methoxy)-9-(tetrahydro-3-furanylmethyl)-9H-purine-2,6-diamine(209 mg) in methanol (21 ml) at room temperature was added 4.0M hydrogenchloride in 1,4-dioxane (3.93 ml) to give a colorless solution. Thereaction mixture was stirred at room temperature for 4 hours. Thereaction mixture was neutralised with 2M NaOH and concentrated in vacuo.The resultant solid was taken up in water (50 ml) and filtered off togive a white solid. This solid was recrystallised from ethanol:water(1:1) and filtered to afford an off-white crystalline solid (105 mg).

MS calcd for (C₁₅H₂₂N₆O₂)⁺=318

MS found (electrospray): (M+H)⁺=319

¹H NMR ((CD3)2SO): δ 9.57 (1H, s), 6.17 (1H, m), 5.98 (2H, s), 3.75 (1H,m), 3.65-3.55 (4H, m), 3.53 (1H, m), 3.22 (2H, m), 2.69 (1H, m), 1.85(1H, m), 1.64 (1H, m), 1.38 (2H, m), 0.68 (1H, m), 0.38 (2H, m), 0.02(2H, m).

Example 556-Amino-2-[(2-cyclopropylethyl)amino]-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one

To a solution ofN2-(2-cyclopropylethyl)-8-(methoxy)-9-(tetrahydro-2H-pyran-3-ylmethyl)-9H-purine-2,6-diamine(198 mg) in methanol (19.1 ml) at room temperature was added 4.0Mhydrogen chloride in 1,4-dioxane (3.57 ml) to give a colorless solution.The reaction mixture was stirred at room temperature for 4 hours. Thereaction mixture was neutralised with 2M NaOH and concentrated in vacuo.The resulting solid was taken up in water (50 ml) and filtered off togive a white solid. This solid was recrystallised from ethanol:water(1:1) and filtered to afford an off-white crystalline solid (113 mg).

MS calcd for (C₁₆H₂₄N₆O₂)⁺=332

MS found (electrospray): (M+H)⁺=333

¹H NMR ((CD3)2SO): δ 9.55 (1H, s), 6.15 (1H, m), 5.97 (2H, s), 3.72-3.61(2H, m), 3.58-3.43 (2H, m), 3.29 (1H, m), 3.22 (2H, m), 3.15 (1H, m),2.03 (1H, m), 1.71-1.57 (2H, m), 1.39 (3H, m), 1.21 (1H, m), 0.69 (1H,m), 0.38 (2H, m), 0.03 (2H, m).

Example 566-Amino-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one(Isomer 1)

To a stirring suspension of2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-(tetrahydro-3-furanylmethyl)-9H-purin-6-amine(814 mg) in methanol (3 ml) was added 4N HCl in dioxan (3 ml). After 3h, the solvents were evaporated and the residue treated with water andneutralised by addition of saturated sodium bicarbonate with stirring.The resulting cream coloured solid was filtered off, washed with waterand dried. The material was suspended in 1:1 ethanol:water (42 ml) butdid not dissolve on boiling/stirring. Complete solution was obtained onadding a further 10 ml ethanol. More water (3 ml) was added and theclear solution allowed to cool to room temperature with stirring. Theresulting cream coloured solid was filtered, washed with 1:1ethanol:water (10 ml) and dried, yield 537 mg.

MS calcd for (C₁₅H₂₁N₅O₃)⁺=319

MS found (electrospray): (M+H)⁺=320

¹H NMR ((CD₃)₂SO): δ 9.89 (1H, s), 6.43 (2H, s), 4.23-4.15 (2H, m),3.79-3.71 (1H, m), 3.69-3.55 (4H, m), 3.54-3.48 (1H, m), 2.76-2.63 (1H,m), 1.94-1.82 (1H, m), 1.68-1.51 (3H, m), 0.83-0.71 (1H, m), 0.0.47-0.36(2H, m), 0.14-0.04 (2H, m).

Example 576-Amino-2-[(2-cyclopropylethyl)oxy]-9-[tetrahydro-3-furanylmethyl]-7,9-dihydro-8H-purin-8-one(Isomer 2)

To2-[(2-cyclopropylethyl)oxy]-8-(methoxy)-9-[tetrahydro-3-furanylmethyl]-9H-purin-6-amine,Isomer 2 (1.45 g) in dry methanol (50 ml) at room temperature and undernitrogen, was added 4.0M hydrochloric acid in 1,4-dioxane (14 ml) in onego. The reaction was stirred at room temperature for 4 hours. Thereaction was neutralised by the addition of 2M aqueous sodium hydroxidesolution and concentrated in vacuo to yield an off white residue. Thiswas taken up in water (40 ml) and filtered to afford a sand colouredsolid. This was recrystallised from water:ethanol, 1:1 (75 ml) to afforda beige solid (765 mg).

MS calcd for (C₁₅H₂₁N₅O₃)⁺=319

MS found (electrospray): (M+H)⁺=320

¹H NMR ((CD₃)₂SO): δ 9.79 (1H, s), 6.33 (2H, s), 4.09 (2H, t), 3.66 (1H,m), 3.58-3.47 (4H, m), 3.42 (1H, m), 2.60 (1H, m), 1.78 (1H, m), 1.53(1H, m), 1.47 (2H, q), 0.67 (1H, m), 0.32 (2H, m), 0 (2H, m).

Example 586-Amino-2-(butylamino)-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-onehydrochloride hydrate

6-Amino-2-(butylamino)-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one(1.00 g) in a round bottom flask (100 mL) was dissolved (with sonicationto break up the solid) in an excess of 4N hydrogen chloride in1,4-dioxane (15 mL). The solution soon formed a suspension that wasstirred at ambient room temperature (21° C.) for 30 minutes before beingevaporated to dryness under reduced pressure. To the resultant solid wasthen added diethyl ether (˜40 mL) to give a suspension, which was thenevaporated under reduced pressure to 18 mbar (water bath, 50° C.) togive an off-white solid (1.11 g). This solid was transferred to a roundbottom flask (250 mL) equipped with magnetic stirrer and refluxcondenser. To the flask was added 2-butanone (111 mL) and the resultantsuspension heated to reflux (external heating, 95° C.). 2-Butanol(racemic) was then added portion wise (1 mL per addition) allowing thesuspension to return to reflux. After the addition of 14 mL of 2-butanola light tan solution was obtained which was refluxed for a few minutes,before the heat source was removed and the solution was allowed to coolwith stirring over a period of 21 hours. The resultant suspension wasthen filtered under suction and the resultant filter-cake then washedwith a minimum volume of acetone. The filter-cake was initially driedunder suction, before then being dried further under vacuo at 50° C.until free from solvent. This gave the title compound (Batch A) as awhite solid (470 mg).

MS calcd for (C₁₅H₂₄N₆O₂)⁺=320

MS found (electrospray): (M+H)⁺=321

1H NMR ((CD₃)₂SO): 12.20 (1H, very broad s), 10.55 (1H, s), 7.77 (2H,broad s) 3.87-3.77 (2H, m), 3.61-3.53 (2H, m), 3.34-3.15 (4H, partiallyoverlapping m), 2.07-1.94 (1H, m), 1.59-1.43 (4H, overlapping m),1.40-1.28 (2H, m), 1.28-1.15 (2H, m), 0.97-0.85 (3H, m). Someexchangeable protons not observed.

A second crop (Batch B) was isolated from the filtrate by filtrationunder suction and the resultant filter-cake was dried under suctionbefore being dried further under vacuo at 50° C. The resultant slightlyimpure product (349 mg) was washed with acetone (4 mL) and then driedunder vacuo at 50° C. (18 hours). This gave little or no change inpurity. This material (338 mg) was suspended in 2-butanone (35 mL) in around bottom flask (100 mL) equipped with magnetic stirrer and refluxcondenser. The resultant suspension was heated to reflux with stirring(external heating, 95° C.) before 2-butanol (racemic) was added (4times, 1 mL) and allowed the resultant suspension to return to reflux.After the addition of additional 2-butanol (racemic, 0.26 mL) theresultant solution was refluxed for 5 minutes before the heat source wasremoved and the solution was allowed to cool to ambient temperature over21 hours. This gave a thick suspension which was cooled in a fridge to3° C. for 2.5 hours. The suspension was filtered under suction and thefilter-cake washed with acetone (8 mL). The filter-cake was air-driedunder suction and then dried further under vacuo at 50° C. until free ofsolvent. This gave the title compound (Batch B) (167 mg).

MS calcd for (C₁₅H₂₄N₆O₂)⁺=320

MS found (electrospray): (M+H)⁺=321

NMR ((CD₃)₂SO): consistent with Batch A.

Additional Supporting Data:

Batch A Batch B Found % Found % C: 48.36, 48.43 (48.40) C: 48.54, 48.58(48.56) H: 7.02, 6.99 (7.01) H: 6.95, 6.97 (6.96) N: 22.35, 22.33(22.34) N: 22.39, 22.35 (22.37) Cl: 9.07, 9.19 (9.13) Cl: 9.13, 9.03(9.08) Best fits: C₁₅H₂₄N₆O₂•HCl•H₂O Calculated % C: 48.06, H: 7.26, N:22.42, Cl: 9.46

Example 596-Amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-onehydrochloride salt Isomer 1

To6-amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one(isomer 1) (1.0 g) at room temperature and under nitrogen, was added4.0M hydrochloric acid in 1,4-dioxane (10.61 ml) and the reactionstirred for 30 minutes. The reaction was then concentrated in vacuo andleft on the rotary evaporator for 2 hours at 50° C. The beige solid wasrecrystallised overnight from 2-butanone (18 ml). The crystals werecollected by suction filtration and dried in vacuo at 50° C. for 30minutes (850 mg).

MS calcd for (C₁₄H₂₂N₆O₂)⁺=306

MS found (electrospray): (M+H)⁺=307

¹H NMR ((CD₃)₂SO): δ 12.37 (1H, br s), 10.64 (1H, br s), 7.85 (2H, brm), 3.75 (1H, m), 3.69-3.56 (4H, m), 3.51 (1H, m), 3.30 (2H, m), 2.66(1H, m), 1.90 (1H, m), 1.63 (1H, m), 1.53 (2H, m), 1.34 (2H, m), 0.90(3H, t). One exchangeable not observed.

Example 606-Amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-onehydrochloride salt Isomer 2

To6-amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one(isomer 2) (1.2 g) at room temperature and under nitrogen was added 4.0Mhydrochloric acid in 1,4-dioxane (12.73 ml) and the reaction stirred atfor 30 minutes. The reaction was then concentrated in vacuo and left onthe rotary evaporator for 2 hours at 50° C. The beige solid wasrecrystallised overnight from 2-butanone (18 ml). The crystals werecollected by suction filtration and dried in vacuo at 50° C. for 30minutes (960 mg).

MS calcd for (C₁₄H₂₂N₆O₂)⁺=306

MS found (electrospray): (M+H)⁺=307

¹H NMR ((CD₃)₂SO): δ 12.36 (1H, br s), 10.62 (1H, br s), 7.82 (2H, brm), 3.75 (1H, m), 3.69-3.58 (4H, m), 3.51 (1H, m), 3.30 (2H, m), 2.66(1H, m), 1.90 (1H, m), 1.63 (1H, m), 1.53 (2H, m), 1.34 (2H, m), 0.90(3H, t). One exchangeable not observed.

Example 616-Amino-2-(butylamino)-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 97 fromN²-butyl-8-(methyloxy)-9-[3-(tetrahydro-2-furanyl)propyl]-9H-purine-2,6-diamine.

LCMS (Method A): t_(RET)=2.50 min; MH⁺=335

Example 626-Amino-2-(butylamino)-9-[4-(tetrahydro-2-furanyl)butyl]-7,9-dihydro-8H-purin-8-one

To a solution ofN²-butyl-8-(methyloxy)-9-[4-(tetrahydro-2-furanyl)butyl]-9H-purine-2,6-diamine(75 mg, 0.207 mmol) in methanol (10 ml) at room temperature was added 4MHCl in 1,4-dioxane (1.324 ml, 5.30 mmol) to give a pale straw colouredsolution. The reaction mixture was stirred at ambient temperatureovernight (16 hours) when LCMS showed the reaction had not proceeded tocompletion. The solvent was removed overnight (16 hours) using anitrogen blowdown unit when LCMS confirmed the presence of the desiredproduct. This crude product was loaded in methanol onto a 5 gaminopropyl SPE cartridge and eluted with methanol over 20 mins. Theappropriate fractions were combined and evaporated under a stream ofnitrogen to give the title compound as a white powder (49 mg).

LCMS (Method B): t_(RET)=1.06 min; MH⁺=349

Example 636-Amino-2-(butylamino)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 fromN²-butyl-8-(methyloxy)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-9H-purine-2,6-diamine.

LCMS (Method B): t_(RET)=0.94 min; MH⁺=321

Example 646-Amino-2-(butylamino)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 fromN²-butyl-8-(methyloxy)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-9H-purine-2,6-diamine.

LCMS (Method B): t_(RET)=0.93 min; MH⁺=321

Example 656-Amino-2-(butylamino)-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 129 fromN²-butyl-8-(methyloxy)-9-[3-(tetrahydro-3-furanyl)propyl]-9H-purine-2,6-diamine.

LCMS (Method B): t_(RET)=0.97 min; MH⁺=335

Example 666-Amino-2-(butylamino)-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 129 fromN²-butyl-8-(methyloxy)-9-[4-(tetrahydro-3-furanyl)butyl]-9H-purine-2,6-diamine.

LCMS (Method B): t_(RET)=1.02 min; MH⁺=349

Example 676-Amino-2-(butylamino)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 129 fromN²-butyl-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-9H-purine-2,6-diamine.

LCMS (Method B): t_(RET)=1.02 min; MH⁺=349

Example 686-Amino-2-(butylamino)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 69 fromN²-butyl-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-9H-purine-2,6-diamine.

LCMS (Method B): t_(RET)=1.26 min; MH⁺=363

Example 696-Amino-2-(butylamino)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one

To a solution ofN²-butyl-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-9H-purine-2,6-diamine(93.13 mg, 0.257 mmol) in methanol (10 ml) was added 4M HCl in dioxane(1.5 ml, 6 mmol) and the mixture stirred at room temperature overnight.The solvent was evaporated under a steam of nitrogen and the residue wasredissolved in methanol (5 ml) and loaded onto a 5 g aminopropyl SPEcartridge and eluted with methanol. The eluant was evaporated under astream of nitrogen to give the title compound (64 mg).

LCMS (Method B): t_(RET)=1.10 min; MH⁺=349

Example 706-Amino-2-(butylamino)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 69 fromN²-butyl-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-9H-purine-2,6-diamine.

LCMS (Method B): t_(RET)=1.19 min; MH⁺=363

Example 716-Amino-2-(butylamino)-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one

To a solution ofN²-butyl-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-8-(methyloxy)-9H-purine-2,6-diamine(135 mg, 0.359 mmol) in methanol (10 ml) was added 4M HCl solution indioxane (2.241 ml, 8.96 mmol) and the mixture was left standing at 20°C. After 6 hours the solvent was evaporated under a stream of nitrogen.The residue was loaded in methanol onto a 10 g aminopropyl SPE cartridgeand eluted with methanol. The solvent was removed by evaporation to givethe title compound (129 mg).

LCMS (Method A): t_(RET)=2.63 min; MH⁺=363

Example 726-Amino-2-(butylamino)-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one

4M HCl in 1,4-dioxane (3 ml, 12.00 mmol) was added in one portion to astirred solution ofN²-butyl-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-8-(methyloxy)-9H-purine-2,6-diamine(40 mg, 0.102 mmol) in methanol (3 ml) at room temperature and themixture stirred under nitrogen overnight. The mixture was thenconcentrated and the residue dissolved in MeOH:DCM (1:1 5 ml) and loadedonto a 2 g aminopropyl SPE cartridge. The cartridge was washed withMeOH:DCM (1:1, 3 column volumes) and the desired fractions wereconcentrated in vacuo to give material of ca. 80% purity. This materialwas dissolved in DCM:MeOH (1:1), applied to a 2 g SCX column and elutedfirstly with MeOH:DCM (3 column volumes) and the product then releasedby 2M ammonia in methanol:DCM (1:1, 3 column volumes). The solvent wasremoved to yield the title compound as a yellow solid (14 mg).

LCMS (Method A): t_(RET)=2.77 min; MH⁺=377

Example 736-Amino-2-(butylamino)-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one

4M HCl in 1,4-dioxane (3 ml, 12.00 mmol) was added in one portion to astirred solution ofN²-butyl-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-8-(methyloxy)-9H-purine-2,6-diamine(130 mg, 0.321 mmol) in methanol (3 ml) at room temperature and themixture stirred under nitrogen overnight. The mixture was thenconcentrated and the residue dissolved in MeOH:DCM (1:1 5 ml) and loadedonto a 2 g aminopropyl SPE cartridge. The cartridge was washed withMeOH:DCM (1:1, 3 column volumes) and the desired fractions wereconcentrated in vacuo to give the title compound as a yellow solid (102mg).

LCMS (Method A): t_(RET)=2.93 min; MH⁺=391

Example 746-Amino-2-(butyloxy)-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 97 from2-(butyloxy)-8-(methyloxy)-9-[3-(tetrahydro-2-furanyl)propyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.85 min; MH⁺=336

Example 756-Amino-2-(butyloxy)-9-[4-(tetrahydro-2-furanyl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 62 from2-(butyloxy)-8-(methyloxy)-9-[4-(tetrahydro-2-furanyl)butyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.02 min; MH⁺=350

Example 766-Amino-2-(butyloxy)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from2-(butyloxy)-8-(methyloxy)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine.

LCMS (Method B): t_(RET)=0.90 min; MH⁺=322

Example 776-Amino-2-(butyloxy)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from2-(butyloxy)-8-(methyloxy)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine.

LCMS (Method B): t_(RET)=0.90 min; MH⁺=322

Example 786-Amino-2-(butyloxy)-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one

To a solution of2-(butyloxy)-8-(methyloxy)-9-[3-(tetrahydro-3-furanyl)propyl]-9H-purin-6-amine(110 mg, 0.315 mmol) in methanol (9 ml) at room temperature was added 4MHCl in dioxane (1.89 ml). The pale yellow solution was stirred at roomtemperature for 18 hrs and then neutralised with 2M sodium hydroxidesolution and evaporated to give a white solid. Trituration with waterand filtration afforded the title compound as a cream solid (74 mg).

LCMS (Method B): t_(RET)=0.94 min; MH⁺=336

Example 796-Amino-2-(butyloxy)-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 129 from2-(butyloxy)-8-(methyloxy)-9-[4-(tetrahydro-3-furanyl)butyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.00 min; MH⁺=350

Example 806-Amino-2-(butyloxy)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 129 from2-(butyloxy)-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.06 min; MH⁺=350

Example 816-Amino-2-(butyloxy)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 69 from2-(butyloxy)-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.10 min; MH⁺=364

Example 826-Amino-2-(butyloxy)-9-[3-(tetrahydro-2H-pyran-3-yl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 62 from2-(butyloxy)-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-3-yl)propyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.01 min; MH⁺=350

Example 836-Amino-2-(butyloxy)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one

To a solution of2-(butyloxy)-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-9H-purin-6-amine(135 mg, 0.358 mmol) in methanol (10 ml) was added 4M HCl in dioxane(2.235 ml, 8.94 mmol) and the mixture was left standing at 20° C. for 18hours. The solvent was evaporated in vacuo to give a white solid whichwas loaded in methanol onto a 10 g aminopropyl SPE cartridge and elutedwith methanol. The appropriate fractions were combined and evaporated invacuo to give the title compound as a white solid (50 mg).

LCMS (Method A): t_(RET)=3.14 min; MH⁺=364

Example 846-Amino-2-(butyloxy)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 69 from2-(butyloxy)-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=0.99 min; MH⁺=350

Example 856-Amino-2-(butyloxy)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 69 from2-(butyloxy)-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.05 min; MH⁺=364

Example 866-Amino-2-(butyloxy)-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 71 from2-(butyloxy)-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-8-(methyloxy)-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.99 min; MH⁺=364

Example 876-Amino-2-(butyloxy)-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 72 from2-(butyloxy)-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-8-(methyloxy)-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.12 min; MH⁺=378

Example 886-Amino-2-(butyloxy)-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from2-(butyloxy)-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-8-(methyloxy)-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.30 min; MH⁺=392

Example 896-Amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-2-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one

To a solution of2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-[2-(tetrahydro-2-furanyl)ethyl]-9H-purin-6-amine(88 mg, 0.253 mmol) in methanol (10 ml) at room temperature was added 4MHCl in 1,4 dioxane (2.106 ml, 8.42 mmol) to give a pale straw colouredsolution. The reaction mixture was stirred at ambient temperatureovernight (16 hours) and then loaded in methanol onto a 5 g aminopropylSPE cartridge and eluted with methanol. The filtrate was evaporated on anitrogen blowdown unit to give the title compound as a white solid (41mg).

LCMS (Method B): t_(RET)=0.95 min; MH⁺=334

Example 906-Amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 97 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-[3-(tetrahydro-2-furanyl)propyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.86 min; MH⁺=348

Example 916-Amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-2-furanyl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 62 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-[4-(tetrahydro-2-furanyl)butyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.03 min; MH⁺=362

Example 926-Amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-3-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 71 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-[2-(tetrahydro-3-furanyl)ethyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.72 min; MH⁺=334

Example 936-Amino-2-[(2-cyclopropylethyl)oxy]-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine.

LCMS (Method B): t_(RET)=0.90 min; MH⁺=334

Example 946-Amino-2-[(2-cyclopropylethyl)oxy]-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine.

LCMS (Method B): t_(RET)=0.90 min; MH⁺=334

Example 956-Amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 78 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-[3-(tetrahydro-3-furanyl)propyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=0.94 min; MH⁺=348

Example 966-Amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 129 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-[4-(tetrahydro-3-furanyl)butyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.00 min; MH⁺=362

Example 976-Amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one

To a solution of2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-9H-purin-6-amine(84.7 mg, 0.234 mmol) in methanol (7.9 ml) at room temperature was added4.0 M HCl in 1,4-dioxane (1.46 ml) to give a pale straw colouredsolution. The reaction mixture was stirred at ambient temperatureovernight (20 hours) and then evaporated in vacuo to give a colourlessoil/gum. This material was re-dissolved in methanol and passed down a 5g aminopropyl SPE cartridge (pre-conditioned in methanol), washedthrough with methanol and evaporated to give the title compound as awhite solid (58.5 mg).

LCMS (Method A): t_(RET)=3.00 min; MH⁺=348

Example 986-Amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 129 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.06 min; MH⁺=362

Example 996-Amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 84 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.25 min; MH⁺=376

Example 1006-Amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 97 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.89 min; MH⁺=348.

Example 1016-Amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 84 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.15 min; MH⁺=3376

Example 1026-Amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=0.94 min; MH⁺=348

Example 1036-Amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 69 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=0.99 min; MH⁺=362

Example 1046-Amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 69 from2-[(2-cyclopropylethyl)oxy]-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.05 min; MH⁺=376

Example 1056-Amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 71 from2-[(2-cyclopropylethyl)oxy]-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-8-(methyloxy)-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.00 min; MH⁺=376

Example 1066-Amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 72 from2-[(2-cyclopropylethyl)oxy]-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-8-(methyloxy)-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.13 min; MH⁺=390

Example 1076-Amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from2-[(2-cyclopropylethyl)oxy]-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-8-(methyloxy)-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.30 min; MH⁺=404

Example 1086-Amino-2-{[(1S)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 84 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2-furanyl)ethyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.91 min; MH⁺=336

Example 1096-Amino-2-{[(1S)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-2-furanyl)propyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.01 min; MH⁺=350

Example 1106-Amino-2-{[(1S)-1-methylbutyl]oxy}-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 97 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.73 min; MH⁺=336

Example 1116-Amino-2-{[(1S)-1-methylbutyl]oxy}-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.75 min; MH⁺=336

Example 1126-Amino-2-{[(1S)-1-methylbutyl]oxy}-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 69 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-3-furanyl)propyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=0.99 min; MH⁺=350

Example 1136-Amino-2-{[(1S)-1-methylbutyl]oxy}-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 69 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-3-furanyl)butyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.05 min; MH⁺=364

Example 1146-Amino-2-{[(1S)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 84 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.03 min; MH⁺=350

Example 1156-Amino-2-{[(1S)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 69 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.11 min; MH⁺=364

Example 1166-Amino-2-{[(1S)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 84 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.29 min; MH⁺=378

Example 1176-Amino-2-{[(1S)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 84 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.91 min; MH⁺=350

Example 1186-Amino-2-{[(1S)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 84 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.17 min; MH⁺=378

Example 1196-Amino-2-{[(1S)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.85 min; MH⁺=350

Example 1206-Amino-2-{[(1S)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 69 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.04 min; MH⁺=364

Example 1216-Amino-2-{[(1S)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 69 from2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.10 min; MH⁺=378

Example 1226-Amino-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-2-{[(1S)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 84 from9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.24 min; MH⁺=378

Example 1236-Amino-9-[3-(2,2-dimethyltetrahydro-2H-Pyran-4-yl)propyl]-2-{[(1S)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.15 min; MH⁺=392

Example 1246-Amino-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-2-{[(1S)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-2-{[(1S)-1-methylbutyl]oxy}-8-(methyloxy)-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.32 min; MH⁺=406

Example 1256-Amino-2-{[(1R)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one

To a solution of2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2-furanyl)ethyl]-9H-purin-6-amine(50 mg, 0.143 mmol) in methanol (10 ml) at room temperature was added 4MHCL in 1,4 dioxane (0.894 ml, 3.58 mmol) to give a pale straw colouredsolution. The reaction mixture was stirred at 37° C. for 3 hours, andthe solvent removed on a nitrogen blowdown unit overnight. The residuewas dissolved in methanol and loaded onto a 2 g aminopropyl SPEcartridge and eluted with methanol. The appropriate fractions werecombined and dried under a stream of nitrogen in a blowdown apparatus togive the title compound as a white solid (26 mg).

LCMS (Method B): t_(RET)=0.99 min; MH⁺=336

Example 1266-Amino-2-{[(1R)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-2-furanyl)propyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.90 min; MH⁺=350

Example 1276-Amino-2-{[(1R)-1-methylbutyl]oxy}-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 97 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.72 min; MH⁺=336

Example 1286-Amino-2-{[(1R)-1-methylbutyl]oxy}-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.73 min; MH⁺=336

Example 1296-Amino-2-{[(1R)-1-methylbutyl]oxy}-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one

To a solution of2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-3-furanyl)propyl]-9H-purin-6-amine(52 mg, 0.143 mmol) in methanol (5 ml) at room temperature was added 4MHCl in dioxane (0.894 ml, 3.58 mmol). The reaction mixture was stirredat room temperature for 18 hrs and concentrated in vacuo to give a whitesolid. This material was dissolved in methanol and loaded onto a 2 gaminopropyl SPE cartridge, eluting with methanol. The solvent wasremoved to give the title compound as a white solid (36 mg).

LCMS (Method B): t_(RET)=0.99 min; MH⁺=350

Example 1306-Amino-2-{[(1R)-1-methylbutyl]oxy}-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 129 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-3-furanyl)butyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.05 min; MH⁺=364

Example 1316-Amino-2-{[(1R)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 125 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.08 min; MH⁺=350

Example 1326-Amino-2-{[(1R)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 129 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.11 min; MH⁺=364

Example 1336-Amino-2-{[(1R)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 84 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.26 min; MH⁺=378

Example 1346-Amino-2-{[(1R)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 125 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.02 min; MH⁺=350

Example 1356-Amino-2-{[(1R)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 125 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.13 min; MH⁺=378

Example 1366-Amino-2-{[(1R)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-9H-purin-6-amine.

LCMS (Method A): t_(RET)=2.84 min; MH⁺=350

Example 1376-Amino-2-{[(1R)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 129 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.04 min; MH⁺=364

Example 1386-Amino-2-{[(1R)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 129 from2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.10 min; MH⁺=378

Example 1396-Amino-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-2-{[(1R)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 125 from9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9H-purin-6-amine.

LCMS (Method B): t_(RET)=1.07 min; MH⁺=378

Example 1406-Amino-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-2-{[(1R)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.16 min; MH⁺=392

Example 1416-Amino-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-2-{[(1R)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one

Prepared similarly to Example 73 from9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-2-{[(1R)-1-methylbutyl]oxy}-8-(methyloxy)-9H-purin-6-amine.

LCMS (Method A): t_(RET)=3.33 min; MH⁺=406

Polymorphism

X-ray powder diffraction (XRPD) and differential scanning calorimetry(DSC) were performed on samples of certain compounds of the inventionaccording to the following methods.

XRPD

The X-ray powder diffraction data were acquired on a PANalytical X'PertPro powder diffractometer, model PW3040/60, serial number DY1850 usingan XCelerator detector. The acquisition conditions were: radiation: CuKα, generator tension: 40 kV, generator current: 45 mA, start angle 20°2θ, end angle: 40° 2θ, step size: 0.0167° 2θ, time per step: 31.75seconds. The sample was prepared by mounting a few milligrams of sampleon a Si wafer (zero background) plates, resulting in a thin layer ofpowder.

DSC

The DSC thermograms were obtained using a TA Q1000 calorimeter, serialnumber 1000-0126. The sample was weighed into an aluminium pan, a panlid placed on top and lightly crimped without sealing the pan. Theexperiment was conducted using a heating rate of 10° C. min⁻¹.

Representative XRPD diffractograms of certain compounds of the inventionare shown in FIGS. 1-7. Representative DSC thermograms of certaincompounds of the invention are shown in FIGS. 8-12.

Biological Data

Compounds of the invention were tested for in vitro biological activityin accordance with the following assays:

Assays for the Induction of Interferon from Human Peripheral BloodMononuclear Cells (PBMC)

Assays based on stimulation of human donor blood derived peripheralblood mononuclear cells (PBMC) with test compounds were developed. Afterincubation of test compounds with freshly isolated PBMCs, cellsupernatants were assayed for interferon alpha using an immunoassay withbroad specificity for most IFNα isoforms.

Some donor variability in responses to known interferon inducers wasobserved, hence resiquimod is included in these assays for normalisationpurposes.

Interferon Induction Assay ‘A’ Compound Preparation

Compounds were dissolved in DMSO. Serial 3-fold dilutions of compoundswere prepared for each compound in growth medium (RPMI 1640 mediumsupplemented with 10% (v/v) foetal calf serum (FCS), 100 U/ml penicillinG, 100 μg/ml streptomycin, 10 mM L-glutamine and 1× non-essential aminoacids) in sterile 96-well tissue culture plates. Each compound isassayed in duplicate for each PBMC donor.

Each assay included a positive control (resiquimod) and a negativecontrol (growth medium). Data are expressed for each compound as EC₅₀(calculated as the concentration of compound required to give 50%maximal induction of interferon alpha) and as relative activity comparedwith an EC₅₀ calculated for resiquimod in the same donor and experiment.

Preparation of PBMCs.

Blood samples were obtained from two human donors. 25 ml volumes ofwhole blood were overlaid onto 15 ml Histopaque® in ACCUSPIN™ tubes,centrifuged at 2100 rpm for 20 min and the band at theplasma/Histopaque® interface carefully removed. The collected cells werewashed twice with PBS (centrifuged at 2100 rpm for 10 min) andresuspended in 10 ml growth medium. A 1:20 dilution of the cells intrypan blue was prepared and counted. The PBMCs were then diluted togive a final concentration in each well of 2×10⁶ cells/ml in 100 μl/wellwhen added to the diluted compounds.

The cell preparations were incubated for 24 h at 37° C. in 5% CO₂. Thecell medium from each well was then transferred to a 96 well filterplate and the cell free supernatant was collected into a new 96 wellplate under vacuum. These supernatants were stored at −20° C. prior toanalysis.

Assay for Interferon Alpha

A multi-isoform immunoassay was used to quantify interferon alpha inPBMC supernatants. For direct quantification of interferon alpha, astandard line of recombinant human interferon alpha 2a (PBLlaboratories) was included in each assay.

A rabbit polyclonal antibody against human IFN-alpha (catalogue number31101, Stratech Scientific) was diluted 1:6400 in phosphate bufferedsaline (PBS) and 20 μl was added to each well of a Meso-Scale® Discovery(MSD®) single small-spot 96-well GAR plate. The plate was incubated for1 h at room temperature with vigorous shaking. Following three washeswith PBS, 20 μl of cell supernatant were added to each well of theplate. The plate was then incubated for 1 h at room temperature withvigorous shaking. A pair of monoclonal antibodies to IFN-alpha(catalogue numbers 21100 and 21112, Stratech Scientific), labelled withsulfo-TAG were diluted 1:500 in growth medium and 20 μl added to eachwell of the plate. The plate was further incubated for 1 h at roomtemperature with vigorous shaking. Following three washes with PBS, 150μl of ×2 T buffer (MSD®) was added to each well and the plate was thenread on an MSD® Sector 6000 plate reader.

IFNα concentrations in supernatants were quantified from a standard lineconstructed using recombinant IFNα 2a. The limit of detection in thisassay is approximately 1 pg/ml.

Interferon Induction Assay ‘B’ Preparation of PBMCs.

Blood samples of up to 200 ml were obtained from healthy human donors.Whole blood in 25 ml volumes was overlaid onto 15 ml Ficoll® gradientsin Leucosep™ tubes, and centrifuged at 1000 g for 20 min. Cells in theband at the plasma/Histopaque® interface were carefully removed andwashed twice with PBS (centrifuged at 400 g for 5 min to harvest). Thefinal pellet was resuspended in freezing medium (90% Heat-inactivatedserum, 10% DMSO) to a cell concentration of 4×10⁷ cells/ml. Theresuspended cells were then cryopreserved (frozen) using a ratecontrolled freezer, and stored at −140° C. for up to 4 months.

Assay for Interferon Alpha

Immediately prior to assay, vials of cryopreserved (frozen) PBMCs werethawed rapidly in a water bath at 37° C. A 1:10 dilution of the cells intrypan blue was prepared and counted. The PBMCs were then diluted ingrowth media [RPMI 1640 containing 10% fetal calf serum (invitrogen),Penicillin+Streptavidin (Gibco cat. #25030-024, 1:50), L-Glutamine 2 mM,and 1000 units/ml recombinant human IFN-gamma (Preprotech catalogue#300-02)] to a density of 1×10⁶ cells/ml, and dispensed to 384-wellclear Greiner polypropylene plates containing 0.25 μl DMSO or testcompound dissolved in neat DMSO. Top final concentration of compound wastypically 50 μM. Plates were incubated for 24 h at 37° C. in 5% CO₂.

A multi-isoform immunoassay was used to quantify interferon-alpha inPBMC supernatants. Rabbit polyclonal antibody against human IFN-alpha(catalogue number 31101, Stratech Scientific) was diluted 1:10000 inassay buffer (RPMI 1640 containing 10% fetal calf serum, Invitrogen) and20 μl was added to each well of an MSD® (Meso-Scale® Discovery) singlesmall-spot 384-well GAR (goat anti-rabbit antibody coated) plate. Theplate was incubated for 1 h at room temperature with vigorous shaking.Following three washes with PBS, 20 μl of cell supernatant were added toeach well of the plate. The plate was then incubated for 1 h at roomtemperature with vigorous shaking. A pair of monoclonal antibodies toIFN-alpha (catalogue numbers 21100 and 21112, Stratech Scientific) werelabelled with sulfo-TAG (MSD®), diluted 1:1000 in assay buffer and 20 μladded to each well of the plate. The plate was further incubated for 1 hat room temperature with vigorous shaking. Following three washes withPBS, 30 μl of ×2 T buffer (MSD®) was added to each well and the platewas read on an MSD® Sector 6000 plate reader.

Data were normalised to internal plate controls of 1 uM resiquimod(n=16) and DMSO (n=16). pEC50 values were derived by 4-parameter curvefit with IRLS in ActivityBase, from 11-point, two-fold serial dilutionof test compounds.

Inhibition of Hepatitis C Virus Replication by Supernatants fromCompound-Stimulated Human Peripheral Blood Mononuclear Cells (PBMC).

An assay was established to measure the antiviral activity insupernatants from human PBMC which had been previously stimulated withcompounds.

Activity assays were conducted using an Huh-7 cell linestably-transfected with a dicistronic replicon, comprising the HCVCon1-ET construct (Pietschmann et al., 2002 J. Virol. 200276(8):4008-21) and the firefly (Photinus pyralis) luciferase gene,obtained from ReBLikon GmbH, Germany.

1.5×10⁴ HCV ET replicon cells per well were grown in 96-well platesovernight in 90 microlitres of cell culture medium. Ten microlitres ofthree-fold dilutions of PBMC supernatants generated above (stimulationof human donor blood-derived peripheral blood mononuclear cells (PBMC)with test compounds) were added to the ET cells. Following a 48-hourincubation, assay medium was removed and luciferase activity measured inthe cell monolayers using the SteadyLite™ assay system (Perkin Elmer).EC₅₀ values were calculated as the compound concentration giving a PBMCsupernatant which was able to inhibit HCV replication by 50% comparedwith a supernatant from unstimulated PBMC cultures.

Inhibition of Ovalbumin (OVA)-Induced Acute Pulmonary Inflammation.

Female BALB/c mice (18-20 g) were inoculated on days 0 and 14, with 10μg OVA adsorbed to 2 mg aluminium hydroxide in a volume of 0.2 mlphosphate buffered saline (PBS) via the intra-peritoneal route. On days24-26, mice were intra-nasally challenged with 50 μl of either saline orOVA (formulated as above) under general anaesthesia.

Interferon-inducing test compounds were dosed at 5 mg/kg orally in avehicle consisting of 0.2% Tween™ 80 in saline. Doses were given oncedaily on days 23 to 27 with the initial dose 24 h prior to the firstchallenge. On the days of challenge, animals were dosed with compound orvehicle one hour after challenge. Animals therefore received a total of5 doses.

Dexamethasone was used as a positive control dosed at 10 mg/kg orally inthe same vehicle once daily on days 24 to 27 with the initial dose 1 hprior to the first challenge. Animals therefore received a total of 4doses.

Animals were killed on day 28 (48 hours post last saline or OVAchallenge) and bronchoalveolar lavage (BAL) was performed with 5×1 ml(0.1% bovine serum albumin, 10 mM EDTA in PBS) and pooled. Numbers oflymphocytes, macrophages, eosinophils and neutrophils in BAL wereidentified by light scatter flow cytometry and quantified.

Results

In Interferon Induction Assay ‘A’, Examples 1 to 60 had a mean EC₅₀ ofbetween 0.01 to 19 uM.

In Interferon Induction Assay ‘B’, Example 13 Isomer 1, Example 13Isomer 2, Example 16 Isomer 1, Example 16 Isomer 2, Example 26 Isomer 1,Example 26 Isomer 2, Example 27 Isomer 1, Example 27 Isomer 2, andExamples 61-141 also had a mean EC₅₀ of between 0.01 to 10 uM.

Replicon Assay

In the above replicon assay, Examples 1 and 4 had a mean EC₅₀ of 0.043uM and 1.05 uM respectively.

Ovalbumin-Induced Acute Pulmonary Inflammation Model

In the above ovalbumin-induced acute pulmonary inflammation model,compared with saline treated controls, Example 4 reduced lymphocyte,eosinophil and neutrophil counts in BAL by 66%, 72% and 50%respectively. In the same experiment dexamethasone reduced lymphocyte,eosinophil and neutrophil counts in BAL by 87%, 92% and 68%respectively.

In the above ovalbumin-induced acute pulmonary inflammation model,compared with saline treated controls, Example 12 reduced lymphocyte,eosinophil and neutrophil counts in BAL by 68%, 67% and 58%respectively. In the same experiment dexamethasone reduced lymphocyte,eosinophil and neutrophil counts in BAL by 86%, 86% and 65%respectively.

1. A method for the treatment of allergic rhinitis, which methodcomprises administering an effective amount of a compound according toFormula (I):

or a pharmaceutically acceptable salt or solvate thereof; wherein R¹ isC₁₋₈alkylamino, C₁₋₈alkoxy, C₃₋₇cycloalkylC₁₋₆alkylamino,C₃₋₇cycloalkylC₁₋₆alkoxy, C₁₋₃alkoxyC₂₋₃alkoxy, or Het^(b)-C₁₋₃alkoxy;Het^(b) is a 5- or 6-membered saturated aliphatic heterocyle containingone oxygen atom; R² is —(CH₂)_(n)-Het; n is an integer having a value of1 to 4; Het is a 5- or 6-membered saturated aliphatic heterocyclecontaining one oxygen heteroatom, which heterocycle may be substitutedby one or two C₁₋₄alkyl groups.
 2. The method according to claim 1wherein R¹ is C₁₋₆alkylamino, C₁₋₈alkoxy, C₃₋₇cycloalkylC₁₋₆alkylamino,C₃₋₇cycloalkylC₁₋₆alkoxy, C₁₋₃alkoxyC₂₋₃alkoxy, or Het^(b)-C₁₋₃alkoxy.3. The method according to claim 1 wherein R¹ is n-butoxy, n-butylamino,2,2-dimethylpentyloxy, n-pentylamino, 3-methylbutoxy, 2-methylbutoxy,1-methylbutoxy, 2-methylbutylamino, 3-methylbutylamino,1-methylbutylamino, 2-(cyclopropyl)ethoxy, 2-(ethoxy)ethoxy,(1-methyl-2-methoxy)ethoxy, cyclohexylmethylamino,cyclopentylmethylamino, 2-(cyclopropyl)ethylamino, 2-(methyl)propoxy,cyclohexylmethoxy, methoxyethoxy, (2-tetrahydrofuranyl)methoxy,(2-tetrahydro-2H-pyranyl)methoxy, or 2-(iso-propoxy)ethoxy.
 4. Themethod according to claim 1 wherein n is
 1. 5. The method according toclaim 1 wherein n is
 2. 6. The method according to claim 1 wherein n is3.
 7. The method according to claim 1 wherein n is
 4. 8. The methodaccording to claim 1 wherein n is 1 and Het is tetrahydrofuran-3-yl,tetrahydro-2H-pyran-3-yl, tetrahydro-2H-pyran-4-yl,tetrahydrofuran-2-yl, 2,2-dimethyltetrahydro-2H-pyran-4-yl, ortetrahydro-2H-pyran-2-yl.
 9. The method according to claim 1 wherein nis 2 and Het is tetrahydro-2H-pyran-4-yl, tetrahydrofuran-2-yl,tetrahydro-2H-pyran-3-yl, tetrahydro-2H-pyran-2-yl, ortetrahydrofuran-3-yl.
 10. The method according to claim 1 wherein n is 3and Het is tetrahydro-2H-pyran-3-yl.
 11. The method according to claim 1wherein n is 4 and Het is tetrahydro-2H-pyran-3-yl.
 12. The methodaccording to claim according to claim 1 wherein R¹ is n-butylamino,n-butoxy, or 2-(cyclopropyl)ethoxy.
 13. The method according to claim 1wherein n is 1 and R² is tetrahydro-2H-pyran-4-yl ortetrahydrofuran-3-yl.
 14. The method according to claim 1 wherein R¹ isn-butylamino, n-butoxy, (R)-1-methylbutyloxy, (S)-1-methylbutyloxy, or2-(cyclopropyl)ethoxy.
 15. The method according to claim 1 wherein Hetis tetrahydrofuran-3-yl, tetrahydro-2H-pyran-3-yl,tetrahydro-2H-pyran-4-yl, tetrahydrofuran-2-yl,2,2-dimethyltetrahydro-2H-pyran-4-yl, or tetrahydro-2H-pyran-2-yl. 16.The method according to claim 1 wherein Het is tetrahydro-2H-pyran-4-yl,tetrahydrofuran-2-yl, tetrahydro-2H-pyran-3-yl,tetrahydro-2H-pyran-2-yl, or tetrahydrofuran-3-yl.
 17. The methodaccording to claim 1 wherein Het is tetrahydro-2H-pyran-3-yl.
 18. Themethod according to claim 1 wherein Het is tetrahydro-2H-pyran-3-yl. 19.The method according to claim 1 wherein Het is tetrahydro-2H-pyran-4-yl,tetrahydro-2H-pyran-3-yl, tetrahydro-2H-pyran-2-yl,2,2-dimethyltetrahydro-2H-pyran-4-yl, tetrahydrofuran-3-yl, ortetrahydro-2H-pyran-2-yl.
 20. The method according to claim 1 wherein nis 2 and Het is tetrahydro-2H-pyran-4-yl, tetrahydro-2H-pyran-3-yl,tetrahydro-2H-pyran-2-yl, 2,2-dimethyltetrahydro-2H-pyran-4-yl,tetrahydrofuran-3-yl, or tetrahydrofuran-2-yl.
 21. The method accordingto claim 1 wherein n is 3 and Het is tetrahydro-2H-pyran-4-yl,tetrahydro-2H-pyran-3-yl, tetrahydro-2H-pyran-2-yl,2,2-dimethyltetrahydro-2H-pyran-4-yl, tetrahydrofuran-3-yl, ortetrahydrofuran-2-yl.
 22. The method according to claim 1 wherein n is 4and Het is tetrahydro-2H-pyran-4-yl, tetrahydro-2H-pyran-3-yl,tetrahydro-2H-pyran-2-yl, 2,2-dimethyltetrahydro-2H-pyran-4-yl,tetrahydrofuran-3-yl, or tetrahydrofuran-2-yl.
 23. The method accordingto claim 1 wherein said compound is selected from the list consistingof:6-amino-2-butoxy-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-butoxy-9-(tetrahydro-2H-pyran-2-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-butoxy-9-(tetrahydrofuran-2-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-butylamino-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-butylamino-9-(tetrahydro-2H-pyran-2-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-butylamino-9-(tetrahydrofuran-2-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-butylamino-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-butylamino-9-(tetrahydrofuran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-butylamino-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-butoxy-9-(tetrahydrofuran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-butoxy-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-butoxy-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-butoxy-9-[2-(tetrahydrofuran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-butylamino-9-[2-(tetrahydrofuran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-butoxy-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-butylamino-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2,2-dimethylpentyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-(pentylamino)-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(3-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(1-methylbutyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-methylbutyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(3-methylbutyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(1-methylbutyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-butyloxy-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-butyloxy-9-[(2,2-dimethyltetrahydro-2H-pyran-4-yl)methyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[(2,2-dimethyltetrahydro-2H-pyran-4-yl)methyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-butyloxy-9-[2-(tetrahydro-3-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[2-(tetrahydro-3-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-{[2-(ethyloxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-{[1-methyl-2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-{[2-(ethyloxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-{[1-methyl-2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(cyclohexylmethyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(cyclopentylmethyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)amino]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-methylpropyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(cyclohexylmethyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-{[2-(methoxy)ethyl]oxy}-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-{[2-(methoxy)ethyl]oxy}-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(tetrahydro-2-furanylmethyl)oxy]-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[3-(tetrahydro-2H-pyran-3-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-9-(tetrahydro-2H-pyran-4-ylmethyl)-2-[(tetrahydro-2H-pyran-2-ylmethoxy]-7,9-dihydro-8H-purin-8-one;6-amino-2-({2-[(1-methylethyl)oxy]ethyl}oxy)-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)amino]-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)amino]-9-(tetrahydro-2H-pyran-3-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,and pharmaceutically acceptable salts or solvates thereof.
 24. Themethod according to claim 1 wherein said compound is selected from thelist consisting of:6-amino-2-(butyloxy)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-butylamino-9-(tetrahydro-2H-pyran-4-ylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-(tetrahydro-3-furanylmethyl)-7,9-dihydro-8H-purin-8-one,and pharmaceutically acceptable salts or solvates thereof.
 25. Themethod according to claim 1 wherein said compound is selected from thelist consisting of:6-amino-2-butoxy-9-[2-(tetrahydrofuran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-butylamino-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-butyloxy-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-butyloxy-9-[(2,2-dimethyltetrahydro-2H-pyran-4-yl)methyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[4-(tetrahydro-2-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-ylethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butylamino)-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[4-(tetrahydro-2-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[3-(tetrahydro-2H-pyran-3-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-2-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-2-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-3-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one6-amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-2H-pyran-2-ylethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-2H-pyran-3-ylethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-2H-pyran-4-ylethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-2-{[(1S)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one;6-amino-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-2-{[(1S)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one;6-amino-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-2-{[(1S)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2-furanyl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-{2-[(3S)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-{2-[(3R)-tetrahydro-3-furanyl]ethyl}-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[3-(tetrahydro-3-furanyl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[4-(tetrahydro-3-furanyl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-2-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2H-pyran-2-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-2-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-3-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1R)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-9-[2-(2,2-dimethyltetrahydro-2H-pyran-4-yl)ethyl]-2-{[(1R)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one;6-amino-9-[3-(2,2-dimethyltetrahydro-2H-pyran-4-yl)propyl]-2-{[(1R)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one;6-amino-9-[4-(2,2-dimethyltetrahydro-2H-pyran-4-yl)butyl]-2-{[(1R)-1-methylbutyl]oxy}-7,9-dihydro-8H-purin-8-one;and pharmaceutically acceptable salts and solvates thereof.
 26. Themethod according to claim 1 wherein said compound is selected from thelist consisting of:6-amino-2-(butyloxy)-9-[4-(tetrahydro-2H-pyran-3-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-(butyloxy)-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[3-(tetrahydro-2H-pyran-4-yl)propyl]-7,9-dihydro-8H-purin-8-one,and;6-amino-2-{[(1S)-1-methylbutyl]oxy}-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[2-(tetrahydro-2H-pyran-4-yl)ethyl]-7,9-dihydro-8H-purin-8-one,and;6-amino-2-[(2-cyclopropylethyl)oxy]-9-[4-(tetrahydro-2H-pyran-4-yl)butyl]-7,9-dihydro-8H-purin-8-one;and pharmaceutically acceptable salts or solvates thereof.